function showDiv(){
	if(document.getElementById){
		document.getElementById('LoadingPage').style.visibility= 'visible';
	}
	else{
		if(document.layers){
			document.LoadingPage.visibility = 'visible'; //netscape 4+
		}
		else{
		document.all.LoadingPage.style.visibility = 'visible';
		}//end else
	}//end else
	return;
}
function MM_jumpMenu(targ,selObj,restore){ //v3.0
  eval(targ+".location='"+selObj.options[selObj.selectedIndex].value+"'");
  if (restore) selObj.selectedIndex=0;
}





<form name="form1">
                            <select name="SubMenu" class="p2" onChange="MM_jumpMenu('parent',this,0)" >
                            <option selected value="gDept_comp_by_hour.jsp?id=31965&p_session_id=eeae9e898f"  onClick="showDiv()" >Compliance by Departure Hour </option>
                            <option  value="gDept_comp_by_dcenter.jsp?id=31965&p_session_id=eeae9e898f" onClick="showDiv()">Compliance by Departure Center </option>

                            <option value="gDept_comp_by_major.jsp?id=31965&p_session_id=eeae9e898f" onClick="showDiv()">Compliance by Major </option>
			    </select>
                          </form>