ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false
v6 = (document.getElementById)? true:false

// Verstecken und Anzeigen von Layern //
function showlayer(layerid)
  {
  if (ns4) document.layers[layerid].visibility = "show"
  else if (v6) document.getElementById(layerid).style.visibility = "visible";
  else if (ie4) document.all[layerid].style.visibility = "visible"
  }

function hidelayer(layerid)
  {
  if (ns4) document.layers[layerid].visibility = "hide"
  else if (v6) document.getElementById(layerid).style.visibility = "hidden";
  else if (ie4) document.all[layerid].style.visibility = "hidden"
  }

// Plausibiltätsabfrage für HardWare-Profile:
function CheckInput() 
  {
  for(i=0; i<16; ++i)
  	if(document.hw_form.elements[i].value == "Bitte wählen...")  {
    	alert("Hardwareprofil: Es wurden nicht alle Felder ausgefuellt!");
        	document.hw_form.elements[i].focus();
        return false;
   }
  return true;
}

// Workaround für Submit Layer in registration.inc.php
function layer_up(layerid, px)
  {
  if (ns4) document.layers[layerid].top = px
  else if (v6) document.getElementById(layerid).style.top = px;
  else if (ie4) document.all[layerid].style.top = px
  }
  
 function layer_down(layerid, px)
  {
  if (ns4) document.layers[layerid].top = px
  else if (v6) document.getElementById(layerid).style.top = px;
  else if (ie4) document.all[layerid].style.top = px
  }