Use JavaScript to evaluate webMathematica tags?

Question

In my HTML form I have 3 buttons. Each button calls different .mx files, based upon an .mx file data. listplot will be created in another jsp page. I placed all .mx files under WEB-INF/Applications.

I wrote 3 functions in Javascript. Inside these functions I wrote the webMathematica code between <msp:evaluate>tags. However the code doesn't seem to be working inside a Javascript function. I wrote the functions in the following way:

function button1()
    {
        <msp:evaluate>
            Get["Data/first.mx"];
            mxData=first;
        </msp:evaluate>
        var id=document.getElementById("name");
        id.action="second.jsp";
        id.submit();
    }

I called this function in the following way:

 <input type="button" value="Button1" onclick="button1()"/>