Confirmation not working in firefox

[abasyn]

I have a number of text boxes on my page, on form submission I check whether the user has left filling any one of them, if he does he will be prompted through a 'confirm' dialog. if he opts for cancel the focus will move to the empty text box and the submit btn functionality is disabled.

Things seem to work in IE but not in Firfox (I am using v 2.0.0.3).

Here is my chunk of javascript func which does it:

function chkMessage()
                {
 
                    var ctlnames= document.getElementById("hdnMsg");
                    var ctlTextBoxes = ctlnames.value.split(",");
                    if (ctlTextBoxes.length > 0)
                    {
                      for(var i=0; i<ctlTextBoxes.length-1; i++)
                      {
                            var txtMsg=    document.getElementById(ctlTextBoxes[i]);  
                            if (txtMsg.value == '' || txtMsg.value.substr(0, 27) == 'Enter your personal message' )
                                if(!confirm("Do you want to continue without entering a personal message?"))
                                {
                                    var obj =document.getElementById("cmdCheckOut");
                                    obj.disabled=true;
                                    txtMsg.focus();
                                    return false;
                                }
                                else
                                    return true;
                      }
                    }
                  }
 

is it the disabled property which is not working in fire fox or what?

here is where i call it

<asp:ImageButton ID="cmdCheckout" Runat="server"  CausesValidation="False" OnClientClick="return chkMessage();"></asp:ImageButton>

[acoder]

The thing to check would be the textbox IDs. Do they match with the strings taken from the hidden input?