How to solve problem when use jquery datepicker and validation in the same time

Question

When I used datepicker with trigger icon so that users could choose date from clicking this icon or type directly in textbox (txtDate), I also used jquery validation to require textbox must be not empty. But when a user submit the form with empty textbox (txtDate.Text=""), the error message of validation push trigger icon to the right. Could you tell me the solution? Thank you very much!