function c(z) {
 var strURL = "c.php?zone="+z;
 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.send('');
}