function changeDiv(num)
  {
     if(num=="1")
	 {
	    document.getElementById("c1").className="on1";
		document.getElementById("c2").className="out1";
		document.getElementById("c3").className="out1";	
		document.getElementById("m1").style.display="block";
		document.getElementById("m2").style.display="none";
		document.getElementById("m3").style.display="none";

	 }
	 if(num=="2")
	 {
	    document.getElementById("c2").className="on2";
		document.getElementById("c1").className="out2";
		document.getElementById("c3").className="out2";	
		document.getElementById("m2").style.display="block";
		document.getElementById("m1").style.display="none";
		document.getElementById("m3").style.display="none";
	 }
	 if(num=="3")
	 {
	    document.getElementById("c3").className="on3";
		document.getElementById("c2").className="out3";
		document.getElementById("c1").className="out3";	
		document.getElementById("m3").style.display="block";
		document.getElementById("m2").style.display="none";
		document.getElementById("m1").style.display="none";
	 }
	
  }