function check_number(sNum) {
   if(isNaN(sNum)) {
      alert('Please enter a numeric value');
      return false;
   } else {
      if(sNum < 0) {
         alert('Please enter a value greater than zero');
         return false;
      }
   }
}

function CopyDate(sFrom, sTo)
{
	CopyField(sFrom + "_day", sTo + "_day");
	CopyField(sFrom + "_month", sTo + "_month");
	CopyField(sFrom + "_year", sTo + "_year");
	CopyField(sFrom + "DateA", sTo + "DateA");
	DateWasSet(sTo);

}

function CopyField(sFrom, sTo)
{
	if (eval(sTo + ".value") == "")
		eval(sTo + ".value = " + sFrom + ".value;");
} 

function DateWasSet(sFld)
{
	if (sFld=="document.myForm.Arrival")
	{
		CopyDate("document.myForm.Arrival", "document.myForm.GeneralStart");
		CopyDate("document.myForm.Arrival", "document.myForm.BreakoutStart");
	}
	if (sFld=="document.myForm.Departure")
	{
		CopyDate("document.myForm.Departure", "document.myForm.GeneralEnd");
		CopyDate("document.myForm.Departure", "document.myForm.BreakoutEnd");
	}
}
function GeneralSessionChanged(sNewVal)
{
	

   
   if (((sNewVal == 'yes') && (document.all("av")[1].disabled)) || 
       ((sNewVal == 'no') && !(document.all("av")[1].disabled)))
      for (x=0; x<document.all("av").length; x++)
         document.all("av")[x].disabled = !(document.all("av")[x].disabled);
	
	
	return;
}

function BreakoutChanged(sNewVal)
{
	
		
   
   if (((sNewVal == 'yes') && (document.all("avb")[1].disabled)) || 
       ((sNewVal == 'no') && !(document.all("avb")[1].disabled)))
      for (x=0; x<document.all("avb").length; x++)
         document.all("avb")[x].disabled = !(document.all("avb")[x].disabled);

	
	
	return;
}