var down, cmin, csec;

function Display(min,sec) {
        var disp;
        if(min<=9) disp=" 0";
        else disp=" ";
        disp+=min+":";
        if(sec<=9) disp+="0"+sec;
        else disp+=sec;
        return(disp);
}

function Down() {
	stop();
	run=true;
      document.rets.topic.value="your topic";
	cmin=30;
	csec=1;
      DownRepeat();
}

function DownRepeat() {
        csec--;
        if(csec==-1) { csec=59; cmin--; }
        document.rets.clock.value=Display(cmin,csec);
        if((cmin==0)&&(csec==0)){
		alert("Time is up!");
		counter();
		}
        else{
		 down=setTimeout("DownRepeat()",1000);
		}
}

function stop(){
	clearTimeout(down);
}