I have to do some date validation in asp.net(vb code behind). My situation is, I am using three list boxes, one for date, one for month & one for Year. I want to validate, whether the user selected the correct date format like not 31st for Nov etc & leapyear validation for Feb. How could I do this with asp.net (javascritp)? Do any one having the code for this? At present I have some function in onselectedindexchange event of the year selection. So, I have to combine these two.