ต้องการแนวคิดเกี่ยวกับวันหยุดครับ โดยที่ถ้าหยุดวันจันทร์ถึงวันศุกร์ = หยุด6วัน แต่ถ้าหยุดไม่ถึงก็คิดตามปกติครับ

<SCRIPT language="javascript">
function DateDriff()
{
var diff;
var start = new Array(3);
var end = new Array(3);
var st = document.getElementById('datestart').value;
var en = document.getElementById('dateend').value;
var weekendDayCount = 0;
var spacday = 0;
//Thai DateFormat 15/08/2552 - DD/MM/YYYY
//Split Start -> Date/Month/Year
start[0] = st.substr(0,2);
start[1] = st.substr(3,2);
start[2] = st.substr(6,4);
//Split End -> Date/Month/Year
end[0] = en.substr(0,2);
end[1] = en.substr(3,2);
end[2] = en.substr(6,4);
end[1] -= 1;
start[1] -= 1;
StratDate = new Date( ); 
EndDate = new Date( );
StratDate.setDate(start[0]); 
StratDate.setMonth(start[1]); 
StratDate.setFullYear(start[2]);
EndDate.setDate(end[0]); 
EndDate.setMonth(end[1]); 
EndDate.setFullYear(end[2])
if(StratDate.getTime( ) <= EndDate.getTime( ))
{
if(EndDate.getTime( ) == StratDate.getTime( ))
{
diff = "1";
}
else {
diff = EndDate.getTime( ) - StratDate.getTime( );
diff = Math.floor(diff / (1000 * 60 * 60 * 24))+1;
var vark= StratDate.getDay();
for(cc=StratDate;cc<=EndDate;StratDate.setDate(StratDate.getDate() + 1))
{
if(StratDate.getDay() === 0 || StratDate.getDay() === 6)
{
++spacday ;
}
}
// while(StratDate < EndDate){
// StratDate.setDate(StratDate.getDate() + 1);
// if(StratDate.getDay() === 0 || StratDate.getDay() === 6)
// {
// ++weekendDayCount ;
// }
// }
}
}
else if(EndDate.getTime( ) < StratDate.getTime( ))
{
diff = "0";
}

if(diff==undefined)
document.getElementById("tmdiff").value = "";
else
//document.getElementById("tmdiff").value = diff-weekendDayCount;
document.getElementById("tmdiff").value = diff-spacday;
}
</SCRIPT>