Yes, the problem is with the zorder !!!

 I got a workaround for this problem from Tony Lombardo at Infragistics, and he has apparently submitted a bug report for this. The text (and code) of the email I got from Tony is shown below. The solution seems to work fine, and I now have several dialog windows with other Infragistics controls working perfectly'

<EMail from Tony Lombardo>

Been looking into this deeper.  In my attempts I wasn't able to modify the z-index of the dialog window in a modal scenario, with out some script.  The z-index that you set in CSS only applies for a non-modal scenario it looks like.  I'm not sure if there's a bug here or if that's the intended behavior, but I've fired off a couple of emails to verify.  Either way, here's a bit of trick javscript to force the dialog window to use a z-index that you want.  It replaces one of the WebDialogWindow private functions which is generally a no-no, but until I find a better way to do this through the public API, the script below will have to suffice.  I added mine to the pageLoad client-side function, so that it will get executed during the pageLoad event (fired by AJAX).  The only thing you really need to modify is the line where you see zIndex=100.  In the script included with the product this is 99999.
function pageLoad(args){

$IG.DialogMoveBehavior.prototype._doZ=
function(lid, elem, lidZ)
{
    this._newZ = this._oldZ = $util.getStyleValue(null, 'zIndex', elem);
    if(!lidZ)
        lidZ = $util.toInt($util.getStyleValue(null, 'zIndex', lid), 0);
    if(lidZ < 10)
        lid.style.zIndex = lidZ = 100; //z-index will default to 100 in a modal scenario
    if($util.toInt(this._oldZ, 0) <= lidZ)
        elem.style.zIndex = this._newZ = lidZ + 1;
    return lidZ;
};

}

<End of EMail>

Hope this provides a quickfix for your problems !! (Thank Tony, not me)

Hi,

I Read your solution im also facing same problem. but from the email of tony still i dont know how to put code ane where to put? can you please help me for it! im new in this programing field specially with java!! please tell me exactly where and what i put this function.

This is the code for my web dialog. 

<ig:WebDialogWindow ID="MSG" runat="server" Height="338px" InitialLocation="Centered"

Modal="true" Style="line-height: normal" Width="518px" >

<Header CaptionAlignment="Left" CaptionText="Delegation Details">

<CloseBox Visible="False" />

</Header>

<ContentPane BackColor="White">

<Template>

<div style="position: relative; text-align: center">

<br /><igsch:WebDateChooser id="WebDateChooser1" runat="server" BackColor="White">

<CalendarLayout Culture="English (United States)">

</CalendarLayout>

</igsch:WebDateChooser>

</div>

</Template>

</ContentPane>

</ig:WebDialogWindow>

<script language="javascript" type="text/javascript">

}

It is generally preferable to place in the Head section, but you can place javascript code anywhere. Of course you would need to place it outside of your control:

</script>

The javascript file is just a text file that has a .js extension. Just place the function in the file.

Thank you very much for your replay.

I already using trying have the code which one you sent to me. i copyed from your post only. but still its now working with my form. Im using content page, i have master page.

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">

<script language="javascript" type="text/javascript">

function(lid, elem, lidZ)

if(!lidZ)

if(lidZ < 10)

lid.style.zIndex = lidZ = 100; //z-index will default to 100 in a modal scenario

elem.style.zIndex = this._newZ = lidZ + 1;

</script>

</igsch:WebDateChooser>

</TD></TR><TR><TD style="WIDTH: 100px; HEIGHT: 23px; font-weight: bold; font-size: 10pt;" align="left">

Comment(s)</TD><TD style="HEIGHT: 52px" colSpan=5 align="left"><asp:TextBox id="txtComment" runat="server" Height="53px" Width="306px" TextMode="MultiLine" MaxLength="255"></asp:TextBox></TD></TR><TR><TD style="WIDTH: 100px; font-weight: bold; font-size: 10pt; height: 34px;" align="left"></TD><TD colSpan=5 style="height: 34px" align="left">

&nbsp;<asp:Button ID="btnSave" runat="server" BackColor="White" ForeColor="#0000C0"

Text="Save" ToolTip="Please Click On Button To Update Changes." Width="61px" />

&nbsp; &nbsp;&nbsp;

<asp:Button ID="btnClose" runat="server" BackColor="White" ForeColor="#0000C0" Text="Cancel"

ToolTip="Please Click on Button To Close window." Width="61px" /></TD></TR></TBODY></TABLE>

&nbsp;</div>

</Template>

</ContentPane>

</ig:WebDialogWindow>

Hi Tony,

i have fix the problem with FF by changething the if(lidZ <= 99999) now the script is working for both IE and FF

    function pageLoad(args){
        
        $IG.DialogMoveBehavior.prototype._doZ=
        function(lid, elem, lidZ)
        {
            
            this._newZ = this._oldZ = $util.getStyleValue(null, 'zIndex', elem);

            if(!lidZ)
                lidZ = $util.toInt($util.getStyleValue(null, 'zIndex', lid), 0);
            
            if(lidZ <= 99999)
            {
                lid.style.zIndex = lidZ = 101; //z-index will default to 100 in a modal scenario
            }
            if($util.toInt(this._oldZ, 0) <= lidZ)
            {
                elem.style.zIndex = parseInt(this._newZ = lidZ + 1);
            }
            
            return lidZ;
        };

    }

Thanx 

function pageLoad(args){ 

$IG.DialogMoveBehavior.prototype._doZ=
function(lid, elem, lidZ)
{
    this._newZ = this._oldZ = $util.getStyleValue(null, 'zIndex', elem);
    if(!lidZ)
        lidZ = $util.toInt($util.getStyleValue(null, 'zIndex', lid), 0);
    if(lidZ < 10)
        lid.style.zIndex = lidZ = 100; //z-index will default to 100 in a modal scenario
    if($util.toInt(this._oldZ, 0) <= lidZ)
        elem.style.zIndex = this._newZ = lidZ + 1;
    return lidZ;
};

}

this Script only work with IE, but not in FF, i have enabled Modal="True". but when Modal is not enable controls work fine. what is the fix for this script to work with FF 

thnx