I am using the following code:

<%
'-- Check if Submit button pushed, if not ignore the entire script
If Request.Form("btnAdd") = "Submit" Then

ASP code goes here!

End If
%>

<!-- HTML FORM -->
<html>

<head>
<title></title>
</head>

<body>
</body>
</html>

However, I don't want to use a button. I want to use a gif which the user can click to submit the form. How do I modify the code (If Request.Form("btnAdd") = "Submit" Then) to check when the click event has taken place so that the ASP code that follows can be executed ?