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);
				}
				else 
				{
					updatepage('Loading ...');
				}
			}
			self.xmlHttpReq.send(getquerystring());
		}
	
	function getquerystring() 
		{
			var form     = document.forms['f1'];
			var category = form.category.value;
			qstr = 'category=' + escape(category);  // NOTE: no '?' before querystring
			return qstr;
		}
	
	function updatepage(str){
		document.getElementById("phrase-result").innerHTML = str;
	}