Calendar calling server function

[Todd Lu]

Hi,
I have a datagrid that needs to change when the date changes in my text
box. If I manually type my date in and tab(postback) , this works fine but
when i call a calendar popup window using javascript I can't seem to call
the server side function to change my datagrid. I am currently calling my
calendar through javascript on my onclick event of my button and the date
gets place on my text box very nicely:

function PopupCalendar() { var strWindowFeatures =
"toolbar=no,resize=no,titlebar=no,"; strWindowFeatures = strWindowFeatures +
"location=no,directories=no,status=no,scrollbars=n o,"; strWindowFeatures =
strWindowFeatures + "menubar=no,width=235,height=180,maximize=null ";
newWindow =
window.open('CalendarSelect.aspx?formname=TimeShee tEntry.txtDate','DateSelec
t',strWindowFeatures); }

I need to call a server side sub some how. Does anyone know how to do this?

Sub SubmitBtn_Click(sender As Object, e As EventArgs)
get datagrid info
end sub

Thanks,

Todd