i am trying to open a popup in my screen where i can lock the remain screen so that the user can only select something from my popup or can cancel the popup. Basically i need to pass some value from a jsp form to my popup, that i had done but i also need to lock the remaining screen that i am not able to do so far. Thanks.

This is how i am calling the jQuery

 <a href="#" class="modalInput"  rel="#prompt">Download</a>

This is my Script

<script>
$(document).ready(function() {
var triggers = $(".modalInput").overlay({
    mask: {
        color: '#555555',
        loadSpeed: 200,
        opacity: 0.9
},
closeOnClick: false
});

var buttons = $("#yesno button").click(function(e) {
    var yes = buttons.index(this) === 0;
    triggers.eq(0).html("You clicked " + (yes ? "yes" : "no"));
});

$("#prompt form").submit(function(e) {
        triggers.eq(1).overlay().close();
        var input = $("input", this).val();
        triggers.eq(1).html(input);
        return e.preventDefault();
    });
});
</script>

This is my Form

<font  face=arial  bgcolor=""><b><center>
<form id="myForm" name="myForm" method="post" action="SentMail" onsubmit="return validateForm(this)">
<div class="modal" id="prompt" >
<div id="">
                    <table width="100%" border="0" cellspacing="0" cellpadding="5" align="center">
                      <tr>
                        <td align="right" valign="middle"> </td>
                        <td align="right" valign="middle"><span style="color:#F00">*</span> Mandotary Field</td>
                      </tr>
                      <tr>
                        <td width="28%" align="right" valign="middle"><strong>Name:</strong><span style="color:#F00">*</span></td>
                        <td width="72%" align="left" valign="middle"><label for="textfield"></label>
                          <div class="out-border">
                          <input name="name" type="text" class="comm-text" id="name" style="width:250px" placeholder="Name"/></div></td>
                      </tr>
                      <tr>
                        <td align="right" valign="middle"><strong>Email:</strong><span style="color:#F00">*</span></td>
                        <td align="left" valign="middle"><label for="textfield2"></label>
                          <div class="out-border">
                          <input name="Email" type="text" class="comm-text" id="Email" style="width:250px" placeholder="Email"/></div></td>
                      </tr>
                      <tr>
                        <td align="right" valign="middle"><strong>Contact No.:</strong></td>
                        <td align="left" valign="middle"><label for="textfield2"></label>
                          <div class="out-border">
                          <input name="contact" type="text" class="comm-text" onkeypress="return isNumberKey(event)" maxlength="10" id="contact" style="width:250px" placeholder="Contact Number"/></div></td>
                      </tr>

                      <tr>
                        <td align="left" valign="middle"> </td>
                        <td align="left" valign="middle"><input type="submit" name="signIn" value="Submit" class="button green"> </input>
                      <input type="button" name="signIn" value="Close" class="close"> </input></td>
                      </tr>

                    </table>
                  </div></div>
    </form>
</center></b></font>

You might want to look into jQuery UI - especially Dialog and the modal option.