hi i use database access(2003) and i dont know how to search in my database
i think about something like this :

...
a = Tclients.Rows[j][i].ToString()
if(a == b)
//ok
...

but i dont know if this the true way because that very slow when i check 10000 users.
someone know how?
thanks.

You really want to try to develop a query for your data. Searching serially through a database defeats the purpose of using a database in the first place.

See this post:

http://vbcity.com/forums/t/112704.aspx

to see how to set up C# code to query an Access database. You can either use a "SELECT" statement in your code, or you can set up an Access Query and call that from the C# code.

Good luck!