by writing the connection string on the click event of the 
button. by connection string i mean it's the ado.net 
structure.firstly you have to include the namespace- using 
system.data.sqlclient;
now on the click event of the button( eg u have taken a 
sumbit button ) you will be writting- sqlconnenection con= 
new sqlconnection........then u'll use 
datacommand,dataset,string,databind,gridview.
u can also use read for getting the errors in a specified 
manner.for this u will be using try and the catch then your 
connection string code and then u'll use the finally 
function and then close().