function check_all_checkboxes(idname, checkFlag){
	element = document.getElementById(idname);
	if(element){
		element.checked  = true;
	}
	cnt = 1;
	while(true){
		element = document.getElementById(idname+ "_" + cnt);
		check_flag = false;
		if(element){
			
			element.checked  = checkFlag;
			check_flag = true;
			cnt++;
		}
		if(check_flag==false){
			break;
		}
	}
}