function fnEnableTop()
{
	document.form1.bhsld.value ="n/a";
	document.form1.mhsld.value ="n/a";
	document.form1.thsld.value ="";

	document.form1.bhsld.disabled=true;
	document.form1.bhtld.disabled=true;
	document.form1.mhsld.disabled=true;
	document.form1.mhtld.disabled=true;
	document.form1.thsld.disabled=false;
	document.form1.thtld.disabled=false;
	document.form1.thsld.focus();		
}

function fnEnableBottom()
{
	document.form1.thsld.value ="n/a";
	document.form1.bhsld.value ="";
	document.form1.mhsld.value ="n/a";

	document.form1.thsld.disabled=true;
	document.form1.thtld.disabled=true;
	document.form1.mhsld.disabled=true;
	document.form1.mhtld.disabled=true;
	document.form1.bhsld.disabled=false;
	document.form1.bhtld.disabled=false;
	document.form1.bhsld.focus();		
}

function fnEnableMiddle()
{
	document.form1.thsld.value ="n/a";
	document.form1.bhsld.value ="n/a";
	document.form1.mhsld.value ="";

	document.form1.thsld.disabled=true;
	document.form1.thtld.disabled=true;
	document.form1.bhsld.disabled=true;
	document.form1.bhtld.disabled=true;
	document.form1.mhsld.disabled=false;
	document.form1.mhtld.disabled=false;
	document.form1.mhsld.focus();		
}