function ShowDiv(step)
{
  
  if (step == "step1")
  {
          document.getElementById("step1").style.display = "block";
          document.getElementById("step2").style.display = "none";
          document.getElementById("step3").style.display = "none";
  }
  else if (step == "step2")
  {
	   	  document.getElementById("step1").style.display = "none";
          document.getElementById("step2").style.display = "block";         
          document.getElementById("step3").style.display = "none";
  }
  else if (step == "step3")
  {
          document.getElementById("step1").style.display = "none";
          document.getElementById("step2").style.display = "none";
          document.getElementById("step3").style.display = "block";
  }
  else {
    alert("Σφάλμα: Δεν βρέθηκε το DIV!");
  }
  
}