I have some text box and 1 datetimepicker. The problem is every time I input a data in textbox and I forgot to select the date it will save automatically in data grid view, even i didn't select a date. So I want if I forgot to select the date it will give me an error message or errorprovider in date time picker. So what is the code for this? Sorry about this i cant fine the correct code so i ask here.