JavaScript Coding examples. Dynamic menu - How to create a simple drop down list and button. Javascript comments - How to include comments in a javascript section of a HTML document. JavaScript For Beginners. Shown below is a very simple JavaScript code: document.write(' Hi there.'). HTML For Beginners Javascript For Beginners CSS For Beginners. Using Java. Script and forms . You can use Java. Script to create special effects. You can use Java. Script to make your HTML pages . And you can use Java. Script to enhance HTML forms. This last application is of particular importance. Of all the hats Java. Simple Example Javascript Scripts. It uses a simple form with radio buttons to determine interest. Web Design & Development I. Home; Lessons; Resources; PREVIOUS; NEXT >>> UNIT 5 > MODULE 3. Lesson 2: A Simple Javascript Program Overview. Chapter 13: Simple Web Applications. Although JSP can make it very easy to mix JavaScript, HTML, and Java into one file, it can make maintenance very difficult. Mixing Java code with HTML or JavaScript is a bad idea. JavaScript Scripts & Programs . Contains HTML and Javascript code which constitute a live demo for web developers. Can thank the author enough for this simple, yet powerful. Script can wear, its form processing features are among the most sought and used. Nothing strikes more fear in the heart of a Web publisher than these three letters: C- G- I. CGI (which stands for common gateway interface), is a mechanism for safely transporting data from a client (a browser) to a server. It is typically used to transfer data from an HTML form to the server. With Java. Script at your side, you can process simple forms without invoking the server. And when submitting the form to a CGI program is necessary, you can have Java. Script take care of all the preliminary requirements, such as validating input to ensure that the user has dotted every i. In this column we'll look closely at the Java. Script- form connection, including how to use Java. Script's form object, how to read and set form content, and how to trigger Java. Script events by manipulating form controls. We'll also cover how to use Java. Script to verify form input and sumbit the form to a CGI program. Learning Java. Script. This article is part of the Java. World technical content archive. You can learn a lot about Java. Script programming by reading articles in the Java. Script series, just keep in mind that some of the information is likely to be outdated. The main one being that a Java. Script form relies on one or more event handlers, such as on. Click or on. Submit. These invoke a Java. Script action when the user does something in the form, like clicking a button. The event handlers, which are placed with the rest of the attributes in the HTML form tags, are invisible to a browser that don't support Java. Script. Because of this trait, you can often use one form for both Java. Script and non- Java. Script browsers. Typical form control objects - - also called . Most any reference on HTML will provide you with the details. For use with Java. Script, you should always remember to provide a name for the form itself, and each control you use. The names allow you to reference the object in your Java. Script- enhanced page. The typical form looks like this. Notice I've provided NAME= attributes for all form controls, including the form itself: < FORM NAME=. Elsewhere in the Java. Script you can reference this form by the name myform. The name you give your form is up to you, but it should comply with Java. Script's standard variable/function naming rules (no spaces, no weird characters except the underscore, etc.). ACTION=. As this example is not designed to submit anything, the URL for the CGI program is omitted. METHOD=. In this case the atttibute is puffer as the example form does not submit anything. INPUT TYPE=. This is standard HTML markup. INPUT TYPE=. This is standard HTML markup except for the on. Click handler. on. Click=. When the button is clicked, Java. Script executes the expression within the quotes. The expression says to call the test. Results function elsewhere on the page, and pass to it the current form object. Getting a value from a form object. Let's experiment with obtaining values from form objects. Load the page, then type something into the text box. Click the button, and what you typed is shown in the alert box. Listing 1. Java. Script calls the test. Results function when you click the button in the form. The test. Results function is passed the form object using the syntax this. I've given the form object the name form inside the test. Result function, but you can any name you like. The test. Results function is simple - - it merely copies the contents of the text box to a variable named Test. Var. Notice how the text box contents was referenced. I defined the form object I wanted to use (called form), the object within the form that I wanted (called inputbox), and the property of that object I wanted (the value property). More from Java. World. Want more programming tutorials and news? Get the Java. World Enterprise Java newsletter delivered to your inbox. Setting a value in a form object. The value property of the inputbox, shown in the above example, is both readable and writable. That is, you can read whatever is typed into the box, and you can write data back into it. The process of setting the value in a form object is just the reverse of reading it. Here's a short example to demonstrate setting a value in a form text box. The process is similar to the previous example, except this time there are two buttons. However, you can use Java. Script to read and write values from most other objects (note that Java. Script cannot currently be used to read or write data using the password text box). In addition to text boxes, Java. Script can be used with: Hidden text box (TYPE=. From a user standpoint, hidden text boxes . Rather, hidden text boxes are the means by which special information can be passed between server and client. They can also be used to hold temporary data that you might want to use later. Because hidden text boxes are used like standard text boxes a separate example won't be provided here. Using Radio Buttons. Radio buttons are used to allow the user to select one, and only one, item from a group of options. Radio buttons are always used in multiples; there is no logical sense in having just one radio button on a form, because once you click on it, you can't unclick it. If you want a simple click/unclick choice use a check box instead (see below). To define radio buttons for Java. Script, provide each object with the same name. Java. Script will create an array using the name you've provided; you then reference the buttons using the array indexes. The first button in the series is numbered 0, the second is numbered 1, and so forth. Note that the VALUE attribute is optional for Java. Script- only forms. You'll want to provide a value if you submit the form to a CGI program running on the server, however.< INPUT TYPE=. The for loop in the test. Button function cycles through all of the buttons in the . When it finds the button that's selected, it breaks out of the loop and displays the button number (remember: starting from 0). LIsting 3. If you want the form to initially appear with a given radio button selected, add the CHECKED attribute to the HTML markup for that button: < INPUT TYPE=. Specify the index of the radio button array you want to checked. Therefore they are a bit easier to use. Using Java. Script you can test if a check box is checked using the checked property, as shown here. Likewise, you can set the checked property to add or remove the checkmark from a check box. In this example an alert message tells you if the first check box is checked. The value is true if the box is checked; false if it is not. Listing 4. Specify the name of the checkbox you want to check, as inform. Using Text Areas. Text areas are used for multiple- line text entry. The default size of the text box is 1 row by 2. You can change the size using the COLS and ROWS attributes. Here's a typical example of a text area with a text box 4. TEXTAREA NAME=. This is done with the value property.
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