function validateRequired(field, field_name) {
	if(field.value == "") {
		alert(field_name + " is required.");
		field.focus();
	    return false; // bad 
	} 
	return true;
}

function validateMaxLength(field, field_name, maxlength) {
	if(field.value.length > maxlength) {
		alert(field_name + " may only be " + maxlength + " characters.");
		field.focus();
	    return false; // bad length
	} 
	return true;
}

function validateNumeric(field, field_name) {
	if(isNaN(field.value)) {
		alert(field_name + " must be a numeric value.");
		field.focus();
	    return false; // bad 
	} 
	return true;
}

function validateMinNum(field, field_name) {
	if(field.value<1) {
		alert(field_name + " must be greater than 0");
		field.focus();
	    return false; // bad 
	} 
	return true;
}

function validateEmail(field, field_name) {
	var atCounter = 0;
	var dotCounter = 0;
	var atPlace = 0;
	var dotPlace = 0;

	if(field.value == "") {
		alert(field_name + " is required.");
		field.focus();
	    return false; // bad email
	} 
	for (x=0; x<field.value.length; x++) {
		var oneChar = field.value.charAt(x);
		if (oneChar == "@") {
			atCounter++;
			atPlace = x;
			}
		if (oneChar == ".") {
			dotCounter++;
			dotPlace = x;
			}
	}
	if (atCounter == 0 || dotCounter == 0 || atPlace > dotPlace || dotPlace- atPlace == 1) {
		alert("Please enter a valid e-mail address.");
		field.focus();
	    return false; // bad email
	}
	return true; // good email
}