Show div in button click with validators but before postback

 Hi,

I have a fileupload control a RegularExpressionValidator, a RequiredFieldValidator and a button.

I just want to be able to show an hidden div when the fileupload is ready (has valid file) and the user click the asp button.

Im able to show the hidden div before the postback with onclientclick but it's not what i want.

I tried this in the button click event :

ClientScript.RegisterStartupScript(Me.GetType(), "show", String.Format("show('DivLoading');"), True)

But it occurs after the postback.

Remember that the validators of the fileupload have to be ok to show the hidden div.

Any ideas?
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