function checkEmptyField(field) {
	var value1=field.value.toString();
	value1=value1.replace(/(^\s*)|(\s*$)/g, "");
	if (value1 == "" || value1.length < 1 ) {
		field.focus();
		field.select();
		field.value=value1;
		return false;
	}else{
		return true;
	}
}

function checkEmail(field) {
	var email_string=field.value;
	var reMail;
	reMail = /^[0-9a-zA-Z]([-_.]?[0-9a-zA-Z])*@[0-9a-zA-Z]([-.]?[0-9a-zA-Z])*\.[a-zA-Z]{2,4}$/;
	if (!email_string.match(reMail)) {
		field.focus();
		field.select();
		return false;
	}
}

var checkflag = "false";
function check_uncheck_all(field) {
	if (checkflag == "false") {
		for (i = 0; i < field.length; i++) {
			field[i].checked = true;}
			checkflag = "true";
		return true; }
		else {
		for (i = 0; i < field.length; i++) {
			field[i].checked = false; }
			checkflag = "false";
		return true; }
}

function uncheck_all(field) {
		for (i = 0; i < field.length; i++) {
			field[i].checked = false; }
			checkflag = "false";
		return true;
}

function show_hide_block(a) {
	obj=document.getElementById(a);
	if (obj.style.display=='none') {
		obj.style.display='block';
	}else{
		obj.style.display='none';
		}
}