render_html = function(output, regionId, append){
	if(append == undefined || typeof append != "boolean"){
		append = false;
	}
	if(output == undefined || typeof output != "string"){
		output = "";
	}
	if(regionId == undefined || typeof regionId != "string"){
		if(document.write){
			document.write(output);

			return true;
		}else{
			alert('Unable to render html; document.write unavailable, and no region is defined');
		}
	}else{
		if(document.getElementById){
			if(document.getElementById(regionId) != null){
				if(append){
					document.getElementById(regionId).innerHTML += output;
				}else{
					document.getElementById(regionId).innerHTML = output;
				}
			}else{
				alert('Unable to render html; region \''+ regionId +'\' doesn\'t exist');
			}
		}else{
			alert('Unable to render html; region \''+ regionId +'\' specified, but document.getElementById is unavailable');
		}	
	}

	return false;
}




function str_replace(search, replace, subject){
	return subject.replace(new RegExp(search,"g"), replace);
}


function enable(id) {
	document.getElementById(id).disabled = false;
}

function disable(id) {
	document.getElementById(id).disabled = true;
}

function show(id, mode) {
	if(typeof mode == "undefined"){
		mode = "block";
	}
	document.getElementById(id).style.display = mode;
}

function hide(id) {
	document.getElementById(id).style.display = "none";
}


function select_by_value(control, text) {
	var i   = 0;
	var len = control.options.length;

	for(i = 0; i < len; i++){
		if(control.options[i].value == text){
			control.selectedIndex = i;
			return true;
		}
	}

	return false;
}

function is_array(arr){
	return (typeof arr == "object" && arr.length);
}

function trim(str) {
	return (str.replace(/^(\s)*/, '')).replace(/(\s)*$/, '');
}