frontend.html to backend python.py

frontend.html + utils.js    with backend python script coefficient.py

<head>
    <script type="text/javascript" src="utils.js"></script>


</head>
<body>
<center>
    <h2> Newtonian Coefficient</h2>
    <p/>
    <input type="text" name="filename" value="input.dat" onblur="ClearDefValue (this)" onfocus="SetDefValue (this)" />
    <input type="button" width="15" value="run" onclick="RunExe();"/></input>
    </p>

<div style="display: block; width: 100px; height: 20px; overflow: hidden;">
<button style="width: 110px; height: 30px; position: relative; top: -5px; left: -5px;">
<a href="javascript: void(0)">Upload File</a></button>
<input type="file" id="upload_input" name="upload" style="font-size: 50px; width: 120px; opacity: 0; filter:alpha(opacity: 0);  position: relative; top: -40px;; left: -20px" />

</div>

<script type="text/javascript">
function RunExe()
{
alert("In fun RunExe()..");
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
alert("Done");

var exe = window.Components.classes['@mozilla.org/file/local;1'].createInstance(Components.interfaces.nsILocalFile);
exe.initWithPath("coefficient.py");
alert("exe");
var run = window.Components.classes['@mozilla.org/process/util;1'].createInstance(Components.interfaces.nsIProcess);
run.init(exe);
var parameters = [""];
run.run(false, parameters,parameters.length);
alert("in function RunBat");

}
<b> kappa front end study </b><br>

    </center>
    </body>


Utils.js
function ClearDefValue (input) {
        if (input.value == '')  {
            input.value = input.defaultValue;
        }
}
function SetDefValue (input) {
        if (input.value == input.defaultValue) {
            input.value = '';
        }
}