function enableOverlay() {
	document.getElementById('overlaydim0').style.width  = screen.width  + 'px';
	document.getElementById('overlaydim0').style.height = screen.height + 'px';
	document.getElementById('overlay0').style.display = 'inline';
}

function disableOverlay() {
	document.getElementById('overlay0').style.display = 'none';
}

function submitOnEnter(field, neighbour, e) {  
	var keyCode;
	if(window.event) keyCode = window.event.keyCode; // IE
	else if(e) keyCode = e.which; //Netscape, Mozilla, Firefox 	   				
	else return true;
	
	if(keyCode == 13 && field.value.length > 0 && neighbour.value.length > 0){
		field.form.submit(); 
		return false;
	} else{
		return true;
	}
}

function initXMLHttpRequest() {
    http_request = false;
    if (window.XMLHttpRequest) {
        http_request = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
        try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                http_request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
        }
    }
    return http_request;
}
function openWindow(url,title)
{
    	window.open(url,'','scrollbars=yes,width=750');
}