var flag=33;
function change()
{
    // document.getElementById("but_about").style.visibility = "hidden";
	 //document.getElementById("but_play").style.visibility = "visible";
	 document.getElementById("text_payback").style.visibility = "visible";
	 document.getElementById("content").style.visibility = "hidden";
	 document.getElementById("but_about").style.backgroundImage='url(images/+about_05.gif)';
	  flag=22;
	  //alert(document.getElementById("but_about").style.backgroundImage.value);
}

function change_back()
{
 	// document.getElementById("but_about").style.visibility = "visible";
	 //document.getElementById("but_play").style.visibility = "hidden";
	 document.getElementById("text_payback").style.visibility = "hidden";
	 document.getElementById("content").style.visibility = "visible";
     document.getElementById("but_about").style.backgroundImage='url(images/+about_03.gif)';
      flag=33;
}

function change_all()
{
  // alert(flag);
	if(flag==33){change(); return true;}
	if(flag==22){change_back();return true;}
}