function switchDiv(div_id)
{
  var style_sheet = document.getElementById(div_id);
  var bypass = document.getElementById("bypass");
  
	if (style_sheet && !bypass)
	{
		if (document.getElementById("Survivorship").checked)
			showAll();
		else
			hideAll();
		
		CalcYears();
	}
}	

function hideAll()
{
   changeObjectVisibility("OIS","none");
   changeObjectVisibility("OIG","none");
   changeObjectVisibility("OIA","none");
   changeObjectVisibility("OIH","none");
   changeObjectVisibility("OIT","none");
}

function showAll()
{
   changeObjectVisibility("OIS","");
   changeObjectVisibility("OIG","");
   changeObjectVisibility("OIA","");
   changeObjectVisibility("OIH","");
   changeObjectVisibility("OIT","");
}

function changeObjectVisibility(objectId, newVisibility)
{
	var styleObject = document.getElementById(objectId);
	if(styleObject)
    {
		styleObject.style.display = newVisibility;
		return true;
    } 
    else 
        return false;
}

function CalcYears()
{	
	if (document.getElementById("Survivorship").checked)
	{
		if (document.getElementById("Age").value < document.getElementById("O_Age").value)
			ageofyounger = document.getElementById("Age").value;
		else
			ageofyounger = document.getElementById("O_Age").value;
	}
	else
		ageofyounger = document.getElementById("Age").value;
		
	document.getElementById("frage").value = 100 - ageofyounger;
	
	if (document.getElementById("frage").value == "NaN")
		document.getElementById("frage").value = "0";
}