function changeDiv (id)
{
	for(i=0; i<4; i++)
	{
	   if('div_'+i == id)
	   {
	       document.getElementById('div_'+i).style.display = "block";
	       document.getElementById('div_menu_'+i).style.background = "#e7e7e7";
	       document.getElementById('div_menu_'+i).style.color = "#000000";
	   }
	   else
	   {
	       document.getElementById('div_'+i).style.display = "none";
           document.getElementById('div_menu_'+i).style.background = "#ffffff";
	       document.getElementById('div_menu_'+i).style.color = "#000000";
	   }
	}
}