Member Avatar for kazp 
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="http://ajax.googleapis.com/ajax/lib…
</script>
<script type="text/javascript">
$(document).ready(function () {


    $("button").click(function () {


$("p").css("background-color", "yellow");
});
});
</script>
</head>
<body>
<form id="form1" runat="server">

<h2>This is a heading</h2>
<p style="background-color:#ff0000">This is a paragraph.</p>
<p style="background-color:#00ff00">This is a paragraph.</p>
<p style="background-color:#0000ff">This is a paragraph.</p>
<button>Return background-color of p</button>
</form>
</body>
</html>

** I wrote this code to change color of <p> elements to yellow by jQuery. This code runs fine when I remove the form tag. But with form tag(this code) <p> element change color to yellow and instantly change back to the previous color. What's the reason for that.?

  • 2 Contributors
  • 2 Replies
  • 160 Views
  • 38 Minutes Discussion Span
  • Latest Post Latest Post by kazp
Member Avatar for JorgeM

This is because your button is within the form and it is causing a postback. When the page reloads the element returns back to its color. Your server side code has no knowledge that you changed the color because that happened client side.

If you don't want the postback you can change your code to this....

 $("button").click(function (event) {
      event.preventDefault();
      $("p").css("background-color", "yellow");
 });
Edited by JorgeM
Member Avatar for kazp

thanks that worked ....

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