Bringing up a calender

[Meghna ks]

Hi I have a textfield formatted to accept the Date & time Data type. Now, I'm already having some Date and Time set in the Text Field. Suppose, the user wants to keyin some Date and Time, I need to bring up a Calender from which the user can select the Date and Time OR
How do I format my Textfield to accept Date & Time :
Right now the format is yyyy/mm/dd => So, how do I restrict the user's i/p to yyyy => 9999 max, mm => 12 max, 1 min , dd => 31 max and 1 min
Right now the format is hh/mm/ss/ms => So, how do I restrict the user's i/p to hr => 1min, 12 max, mm => 1min, 60max, ss => 1min, 60 max, ms => 1min and 60max.
I'd greatly appreciate your help.
Thanks
Meghna