在asp：textboxes上的jquery onblur空文本框验证

I have a series of asp:textboxes (about 30) which I wanted to validate if they are empty (when the user goes to other textbox), when the users leave them empty (on blur) I have found tutorials on the net however it is specified only to a few textboxes, how can I achieve this? I have a series of asp:textboxes (about 30) whi