From http://www.w3schools.com (Copyright Refsnes Data)

ASP Procedures

In ASP you can call a JavaScript procedure from a VBScript and vice versa.

Examples

Call a procedure using VBScript
How to call a VBScript procedure from ASP.

Call a procedure using JavaScript
How to call a JavaScript procedure from ASP.

Call procedures using VBScript
How to call both a JavaScript procedure and a VBScript procedure in an ASP file.

Procedures

The ASP source code can contain procedures and functions:

<html>
<head>
<%
sub vbproc(num1,num2)
response.write(num1*num2)
end sub
%>
</head>

<body>
<p>Result: <%call vbproc(3,4)%></p>
</body>

</html>

Insert the <%@ language="language" %> line above the <html> tag to write procedures or functions in another scripting language than default:

<%@ language="javascript" %>
<html>
<head>
<%
function jsproc(num1,num2)
{
Response.Write(num1*num2)
}
%>
</head>

<body>
<p>Result: <%jsproc(3,4)%></p>
</body>

</html>

Differences Between VBScript and JavaScript

When calling a VBScript or a JavaScript procedure from an ASP file written in VBScript, you can use the "call" keyword followed by the procedure name. If a procedure requires parameters, the parameter list must be enclosed in parentheses when using the "call" keyword. If you omit the "call" keyword, the parameter list must not be enclosed in parentheses. If the procedure has no parameters, the parentheses are optional.

When calling a JavaScript or a VBScript procedure from an ASP file written in JavaScript, always use parentheses after the procedure name.