function selection() {

	if( document.getElementById('allUsers').checked)
	{ 
		for( i in document.forms["renewal"].elements) {
			if( document.getElementById('checkbox['+i+']')) {
				if( document.getElementById('checkbox['+i+']').checked == false) {
					document.getElementById('checkbox['+i+']').checked = true;
				}	
			}
		}
	} else {
		for( j in document.forms["renewal"].elements) {
			if(document.getElementById('checkbox['+j+']')) {
				if( document.getElementById('checkbox['+j+']').checked == true) {
					document.getElementById('checkbox['+j+']').checked = false;
				}
			}		
		}
	}

}