problem with validation control

 I have some control and validation control .but when i enter an incorrect mail and press the button i can't see the error message .what should i do  ?

"RegularExpressionValidator1" runat="server" ControlToValidate="txtsend"
ErrorMessage="enter correct email" Style="position: relative; right: -16px; top: 0px;" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"
ValidationGroup="s">


"width: 100px">

"width: 126px">



"width: 100px">
"Label1" runat="server" Style="position: rel ...