//  Sean McDonnell
//  08 July 2010
//  A function to select all GridViewRow CheckBoxex from the Header CheckBox
function SelectAll() {
    var frm = document.forms[0];
    for (i = 0; i < frm.elements.length; i++) {
        if (frm.elements[i].type == "checkbox") {
            frm.elements[i].checked = true;
        }
    }
}