function showHideCourses()
{
   var course_index=document.getElementById("course_selection").value;
   var monavale_row=document.getElementById("monavale_row");
   var crossing_row=document.getElementById("crossing_row");
   var abs_row=document.getElementById("abs_row");
   var monavale_selection;
   var crossing_selection;
   var abs_selection;
   
  if(document.getElementById("CAT_Custom_94248"))
      monavale_selection=document.getElementById("CAT_Custom_94248");
  if(document.getElementById("CAT_Custom_94208"))
      crossing_selection=document.getElementById("CAT_Custom_94208");
  if(document.getElementById("CAT_Custom_94235"))
      abs_selection=document.getElementById("CAT_Custom_94235");

   if(course_index=="-1")
   {
	   monavale_row.style.display="none";
	   crossing_row.style.display="none";
	   abs_row.style.display="none";
           if(document.getElementById("CAT_Custom_94248"))
              monavale_selection.value=" ";
           if(document.getElementById("CAT_Custom_94208"))
             crossing_selection.value=" ";
           if(document.getElementById("CAT_Custom_94235"))
             abs_selection.value=" ";
	   
   }
   else if(course_index=="monavale")
   {
	   monavale_row.style.display="";
	   crossing_row.style.display="none";
	   abs_row.style.display="none";
           if(document.getElementById("CAT_Custom_94208"))
             crossing_selection.value=" ";
           if(document.getElementById("CAT_Custom_94235"))
             abs_selection.value=" ";   
   }
   else if(course_index=="crossing")
   {
	   monavale_row.style.display="none";
	   crossing_row.style.display="";
	   abs_row.style.display="none";
           if(document.getElementById("CAT_Custom_94248"))
              monavale_selection.value=" ";
           if(document.getElementById("CAT_Custom_94235"))
             abs_selection.value=" ";   
   }
   else if(course_index=="abs")
   {
	   monavale_row.style.display="none";
	   crossing_row.style.display="none";
	   abs_row.style.display="";
           if(document.getElementById("CAT_Custom_94248"))
              monavale_selection.value=" ";
           if(document.getElementById("CAT_Custom_94208"))
             crossing_selection.value=" ";   
   }   
}