/* source: http://www.xul.fr/ajax/ajax-demo-exists.html 
*/

	function submitForm(url)
	{ 
	xhr=createXHR();
	document.getElementById("zone").innerHTML="Started...";
 
	xhr.open("HEAD", url, true);
	xhr.onreadystatechange=function() 
	{
		document.getElementById("zone").innerHTML="Wait server...";
		if(xhr.readyState == 4) 
		{
			var value;
			if (xhr.status == 200)
			{ 
				 value = url + " will be displayed shortly...";
			}
			else 
			{
				if(xhr.status==404) 
					value = " The flood map you requresd doesn't exist in the database! Please click the 'Reset' button below to restart. Real time forecast requires a user account for login.";
    	 			else 
					value = "Error, status is " + xhr.status;
			}
			document.getElementById("zone").innerHTML=value;			

		}
	}

	xhr.send(null); 
	} 
	
function createXHR() 
{
    var request = false;
        try {
            request = new ActiveXObject('Msxml2.XMLHTTP');
        }
        catch (err2) {
            try {
                request = new ActiveXObject('Microsoft.XMLHTTP');
            }
            catch (err3) {
		try {
			request = new XMLHttpRequest();
		}
		catch (err1) 
		{
			request = false;
		}
            }
        }
    return request;
}