signup page

Hi ..
I am having signup page that contains username,pwd,confpwd,Email,Address and one save button .
when user enter his details and press save button it should save details in database.
i have done upto here.But my problem is:
if Email Entered already Exsists in database then it should display a message that Email already exists in Database.
For this what i have to write Code .Pls send me the Code .

i want to display user in the FrontEnd Label.

Thank you..

re: signup page

Place a label in the page and keep its visible property to false initially, when the emailid is alredy present in the database and u wanna show the message set the visible proerty to true and set the text to the message

lblMessage.visible=false; (in pageload)

btnSave_click(object sender, EventArgs e)
{
if(mailIdpresent==true)
lblMessage.visible=true;
lblMessage.text="Email Id already exists";
}