function Ch(y) {
	        var qstr;
	        var tmp=document.getElementById("DaMonth")
	        var CurrentMonth=tmp[tmp.selectedIndex].value
	        
	        tmp=document.getElementById("DaYear")
	        var CurrentYear=tmp[tmp.selectedIndex].value
	        
	        
	        
	        if (y!=null) {
	            qstr = "Dat=" + y
	         }
	        else {
	            qstr="DaMonth=" + CurrentMonth + "&DaYear=" + CurrentYear
	        }
	
			addQstr(qstr);
	    //self.location=isolatepage(self.location.href) + qstr
	}
	
	function isolatepage(x) {
	    if (x.indexOf("?")==-1) return x
	    else {
	        tmp=x.substring(0,x.indexOf("?"))
	        return tmp 
	    }
	}
	
function addQstr(x) {
	var tmp=self.location.href;
	var start=tmp.indexOf('?');
	var oldqstr, arrTmp, isolatedpage, newqstr;
	
	newqstr='';
	
	if (start == -1) {
		self.location=tmp + '?' + x
	}
	else {
		isolatedpage=isolatepage(tmp)
		oldqstr=tmp.substring(start+1, tmp.length);
		arrTmp=oldqstr.split("&");
		
		for (i=0; i<arrTmp.length; i++) {
			tmp=arrTmp[i].toLowerCase();
			if (tmp.indexOf('id') > -1) {
				newqstr=tmp;
				break;
			}
		}
		
		if (newqstr.length > 0) self.location=isolatedpage + '?' + newqstr + '&' + x
		else self.location=isolatedpage + '?' + x
	}
}