var http_request = false;
function makeRequest(url, parameters) {
	http_request = false;
	if (window.XMLHttpRequest) { // Mozilla, Safari,...
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) {
			// set type accordingly to anticipated content type
			//http_request.overrideMimeType('text/xml');
			http_request.overrideMimeType('text/html');
		}
	} else if (window.ActiveXObject) { // IE
		try {
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) {}
		}
	}
	if (!http_request) {
		return false;
	}
		
	http_request.onreadystatechange = alertContents;
	http_request.open('POST', url + parameters, true);
	http_request.setRequestHeader('Content-Type','multipart/form-data;');
	http_request.send(null);	
}

function alertContents() {
	if (http_request.readyState == 4) {
		if (http_request.status == 200) {
			result = http_request.responseText;
			displayInfobox(result);
		} else {
			alert('There was a problem with the request.');
		}
	}
}

function submit_form(obj, url) {
	var getstr = "?";
	var error;
	for (i=0; i < obj.elements.length; i++) {
		
		if (obj.elements[i].accept == 'value') {
			//alert(obj.elements[i].accept);
			if (obj.elements[i].value == '') {
				error = true;
				obj.elements[i].style.backgroundColor = '#FFCCCC';
			}
		} else if (obj.elements[i].accept && obj.elements[i].accept != '') {
			if (!eval('obj.elements[i].value.match('+obj.elements[i].accept+')')) {
				error = true;
				obj.elements[i].style.backgroundColor = '#FFCCCC';
			}
		}
		if (obj.elements[i].tagName == "INPUT") {
			if (obj.elements[i].type == "text" || obj.elements[i].type == "hidden" || obj.elements[i].type == "file") {
				getstr += obj.elements[i].name + "=" + Url.encode(obj.elements[i].value) + "&";
			}
			if (obj.elements[i].type == "checkbox") {
				if (obj.elements[i].checked) {
					getstr += obj.elements[i].name + "=" + Url.encode(obj.elements[i].value) + "&";
				} else {
					getstr += obj.elements[i].name + "=&";
				}
			}
			if (obj.elements[i].type == "radio") {
				if (obj.elements[i].checked) {
					getstr += obj.elements[i].name + "=" + Url.encode(obj.elements[i].value) + "&";
				}
			}
		}   
		if (obj.elements[i].tagName == "SELECT") {
			var sel = obj.elements[i];
			if (sel.multiple) {
				var j = 0;
				while(sel.options[j]) {
					if (sel.options[j].selected) { 
						getstr += sel.name + "[]=" + Url.encode(sel.options[j].value) + "&";
					}
					j++;
				}
			}
			else {
				getstr += sel.name + "=" + Url.encode(sel.options[sel.selectedIndex].value) + "&";
			}
		}
		if (obj.elements[i].tagName == "TEXTAREA") {
				getstr += obj.elements[i].name + "=" + Url.encode(obj.elements[i].value) + "&";
		}

	}
	
	if (error) {
		return false;
	}

	makeRequest(url, getstr);
	return true;	
}

var Url = {
    // public method for url encoding
    encode : function (string) {
        return escape(this._utf8_encode(string));
    },
    // public method for url decoding
    decode : function (string) {
        return this._utf8_decode(unescape(string));
    },
    // private method for UTF-8 encoding
    _utf8_encode : function (string) {
        string = string.replace(/\r\n/g,"\n");
        var utftext = "";

        for (var n = 0; n < string.length; n++) {

            var c = string.charCodeAt(n);

            if (c < 128) {
                utftext += String.fromCharCode(c);
            }
            else if((c > 127) && (c < 2048)) {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            }
            else {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }

        }

        return utftext;
    },

    // private method for UTF-8 decoding
    _utf8_decode : function (utftext) {
        var string = "";
        var i = 0;
        var c = c1 = c2 = 0;

        while ( i < utftext.length ) {

            c = utftext.charCodeAt(i);

            if (c < 128) {
                string += String.fromCharCode(c);
                i++;
            }
            else if((c > 191) && (c < 224)) {
                c2 = utftext.charCodeAt(i+1);
                string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                i += 2;
            }
            else {
                c2 = utftext.charCodeAt(i+1);
                c3 = utftext.charCodeAt(i+2);
                string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                i += 3;
            }

        }

        return string;
    }

}