function xmlhttpPost(strURL) 
{
	var xmlHttpReq = false;
    var self = this;
    // Mozilla/Safari
    if (window.XMLHttpRequest) {
        self.xmlHttpReq = new XMLHttpRequest();
    }
    // IE
    else if (window.ActiveXObject) {
        self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
    }
    self.xmlHttpReq.open('POST', strURL, true);
    self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    self.xmlHttpReq.onreadystatechange = function() {
        if (self.xmlHttpReq.readyState == 4) {
            updatepage(self.xmlHttpReq.responseText);
        }
    }
	document.getElementById("result").innerHTML = '<img src="images/1-0.gif" border="0">';
	document.getElementById("result").style.display = "block";
    self.xmlHttpReq.send(getquerystring());
}

function getquerystring() {
	
    var form     = document.forms['frmadd'];
    var word = form.category_id.value;
	qstr = 'category_id=' + escape(word);  // NOTE: no '?' before querystring
	
    return qstr;
}

function updatepage(str){

    document.getElementById("result").innerHTML = str;
}