function $$(id) {
	try {
		var tmp = document.getElementById(id).value;
	}
	
	catch(e) {
		alert("Field " + id + " does not exist!\nvalidation is configured on a field with no ID");
		return false;
	}
	
	if(tmp == "") {
		var field_name = id.replace("_", " ");
		
		alert("Field \"" + field_name + "\" cannot be empty");
		return false;
	}

	return tmp;
}

var required = {
field : [],
add : function(name, type) {
this.field[this.field.length] = [name,type];
},
out : function() {
return this.field;
}
}

var validate = {

check : function() {
var tmp;
// loop all required fields
for(var i=0; i<required.field.length; i++) {
	// check the form field exists
	this.tmp = $$(required.field[i][0]);
	
	if(this.tmp) {
		if(this.checkit(required.field[i][0],required.field[i][1])) {
			// validated okay
		} else {
			alert("Field "+required.field[i][0]+" not valid\n");
			document.getElementById(required.field[i][0]).focus();
			return false;
		}
	} else {
		try {
			document.getElementById(required.field[i][0]).focus();
		}
	
		catch(e) { }
		return false;
	}
} // for
return true;
},

checkit : function(value,type) {
exp : '';
switch(type) {

case "NOT_EMPTY":
if(this.trim($$(value)).length < 1) { return false; } else { return true; }
break;

case "ALPHA":
exp = /^[A-Za-z]+$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "ALPHASPACE":
exp = /^[A-Za-z ]+$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "NUMERIC":
exp = /^[0-9]+$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "NUMERICPLUS":
exp = /(^-*\d+$)|(^-*\d+\.\d+$)/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "ALPHANUM":
exp = /^[a-zA-Z0-9]+$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "ALPHANUMSPACE":
exp = /^[a-zA-Z0-9 ]+$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "EMAIL":
exp = /^[a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "YYYYMMDD":
exp = /^(19|20)[0-9][0-9][- /.](0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "DDMMYYYY":
exp = /^(0[1-9]|[12][0-9]|3[01])[- /.](0[1-9]|1[012])[- /.](19|20)[0-9][0-9]$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

case "MMDDYYYY":
exp = /^(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)[0-9][0-9]$/;
if($$(value).match(exp)==null) { return false; } else { return true; }
break;

default:
exp = new RegExp(type);
if($$(value).match(exp)==null) { return false; } else { return true; }
} // switch
},
trim : function(s) {
return s.replace(/^\s+/, '').replace(/\s+$/, '');
}

}

function $val(id) {
	return document.getElementById(id);
}

function trim(id) {
	$val(id).value = $val(id).value.replace(/^\s+/, '').replace(/\s+$/, '');
}