how to manage insert event in asp.net with mysql

http://pacesoftronix-001-site1.smarterasp.net/
there is registration page in this URL if two user hit the save button of reg at same time how to manage connection.

when i am hitting same page from different place one of them web page have error connection is used by data-reader after i have make exception handling now when i am hitting page there is error."connection must be valid and open"

i didn't use any data reader.then also error comes and when i close con then the another error comes..i don't know how to handle data from web site accessing from different user.
please help.

do you have idea about updlock in sql.i want to implement in mysql database.

its unique but i write code at save button event.if two user hit save button at the same time how it is managed.if i make mysql database table lock when one query is running i can be prevent but i don't know how it will implementable.please help.

but how to managed save event if two user hit button at the same time

let say user A hit save at t time and user B also hit save at t time then how to handle two two query..

no there is error "connection must be valid and open"

do you have idea about updlock in sql.i want to implement in mysql databse.