<Lesson 15> [Contents] <Lesson 17>
16.1 The onChange Event
The onChange event occurs when the users alter the input into form elements, such as a text box. In the following example, we shall show you how this event triggers a pop-up message when the user enters something into a textbox and alter its content.
Click on Example 16.1 to see the output.
When the user loads the web page that contains the script, a text box will appear at the top of the web page. When enters something into the textbox, alters it and then click outside the textbook, he will see a pop-up dialog then reads “You have changed the content”
16.2 The onSelect Event
The onSelect event occurs when the user selects text by dragging the mouse across a certain part of the text. We can write JavaScript code for this event. In Example 16.2, when the user types some characters into the text area and then select a part of the text, the selected will be shown to the user via a pop-up dialog.
Example 16.2
<html>
<head>
<meta http-equiv=”Content-Type” content=”text/html; charset=windows-1252″>
<title>JavaScript Example 16.1: onChange</title>
</head>
<body>
<script>
function SelText()
{
yourtext = document.selection.createRange().text;
window.alert(“You text you have selected is: “+yourtext );
}
</script>
<Form>
<textarea rows=”5″ cols=”20” onSelect=(SelText(this.form))></textarea>
</form>
</body>
</html>
Please click on Example 16.2 to test the output.