function check_uncheck(Val)
{
  var ValChecked = Val.checked;
  var ValId = Val.id;
  var frm = document.forms[0];
  // Loop through all elements
  for (i = 0; i < frm.length; i++)
  {
    // Look for Header Template's Checkbox
    //As we have not other control other than checkbox we just check following statement
    if (this != null)
    {
      if (ValId.indexOf('CheckAll') !=  - 1)
      {
        // Check if main checkbox is checked,
        // then select or deselect datagrid checkboxes
        if (ValChecked)
          frm.elements[i].checked = true;
        else
          frm.elements[i].checked = false;
      }
      else if (ValId.indexOf('deleteRec') !=  - 1)
      {
        // Check if any of the checkboxes are not checked, and then uncheck top select all checkbox
        if (frm.elements[i].checked == false)
          frm.elements[1].checked = false;
      }
    } // if
  } // for
} // function

//Now the Delete confirmation method:

//Listing 5

function confirmMsg(frm)
{
  // loop through all elements
  for (i = 0; i < frm.length; i++)
  {
    // Look for our checkboxes only
    if (frm.elements[i].name.indexOf("deleteRec") !=  - 1)
    {
      // If any are checked then confirm alert, otherwise nothing happens
      if (frm.elements[i].checked)
      return confirm('Are you sure you want to delete your selection(s)?')
    }
  }
   alert('At least one record should be checked');
  return false;
}

function confirmMsg1(frm)
{
  // loop through all elements
  for (i = 0; i < frm.length; i++)
  {
    // Look for our checkboxes only
    if (frm.elements[i].name.indexOf("deleteRec") !=  - 1)
    {
      // If any are checked then confirm alert, otherwise nothing happens
      if (frm.elements[i].checked)
      return confirm('Are you sure you want to approve your selection(s)?')
    }
  }
  alert('At least one record should be checked');
  return false;
}