check all works in Mozilla but not in IE

[needhipandya]

Hi i am using a function to check-uncheck all checkboxes... That works fine in mozilla but doesnt works in IE. Gives "event is null or not an object" error in status bar (in IE)... I have used same function at other places and there it works fine(even in IE). Can anyone tell me wat could be the problem...
The function dat i m using is

protected void chkboxall_Check edChanged(objec t sender, EventArgs e)
{
CheckBox chkboxall = new CheckBox();
chkboxall = (CheckBox)grdvi ewchrgpanel.Hea derRow.FindCont rol("chkboxall" );

if (chkboxall.Chec ked)
{
for (int count = 0; count < grdviewchrgpane l.Rows.Count; count++)
{
CheckBox chkboxchrgpanel = new CheckBox();
chkboxchrgpanel = (CheckBox)grdvi ewchrgpanel.Row s[count].FindControl("c hkboxchrgpanel" );
chkboxchrgpanel .Checked = true;
}
}
else
{
for (int count = 0; count < grdviewchrgpane l.Rows.Count; count++)
{
CheckBox chkboxchrgpanel = new CheckBox();
chkboxchrgpanel = (CheckBox)grdvi ewchrgpanel.Row s[count].FindControl("c hkboxchrgpanel" );
chkboxchrgpanel .Checked = false;
}
}
}