function force_integer(field,keypress) {
	// ie / ns handling
	if (document.all) { key = keypress.keyCode; } else { key = keypress.charCode; }	
	// allow only numbers, period, backspace, delete, etc
	if (key < 48 && key > 0 || key > 57) {
		return false;
	}
}

function validate_email(src) {
	var emailReg = "^[a-z0-9\._-]+@+[a-z0-9\._-]+\.+[a-z]{2,4}$";
	var regex = new RegExp(emailReg);
	return regex.test(src);
}

function validate_time(src) {
	var timeReg = "^[0-9]{2}+:+[0-9]{2}$";
	var regex = new RegExp(timeReg);
	return regex.test(src);
}

function ischecked(fieldname) {
	var checkFound = false;
	for (var counter=0; counter < document.forms['form1'].length; counter++) {
		if ((document.forms['form1'].elements[counter].name == fieldname) && (document.forms['form1'].elements[counter].checked == true)) {
			checkFound = true;
		}
	}
	if (checkFound == false) {
		alert ("Please make a selection first.");
	}
	return checkFound;
}

function layer(display_item) {
	if (document.getElementById(display_item).style.display == 'none') {
	
		var elements = document.getElementsByTagName('div');
		var count = document.getElementsByTagName('div').length;	
		for (i = 0; i < count; i++) {
			if ( elements[i].id.substring(0, 5) == 'layer' ) {
				elements[i].style.display = 'none';
			}
		}
		document.getElementById(display_item).style.display = 'block';
	
	} else {
	
		document.getElementById(display_item).style.display = 'none';

	}
}

function textCounter(field, countfield, maxlimit) {
	if ( field.value.length > maxlimit ) {
		field.value = field.value.substring( 0, maxlimit );
		alert('Limit of '+maxlimit+' characters reached.');
		return false;
	} else {
		countfield.value = maxlimit - field.value.length;
	}
}