How to make a result in a query(with var.) as an var in ASP.NET?

[VKEI]

sorry,i am very very to ASP.NET
now ,i need to make 2 funtions on an ASP.NET c# page working with an SQL server (using Visual Web Developer 2010 Express)

the 1st one is a simple serach and i've done

the 2nd thing is an update , the sp is like:(it works in SQL)

UPDATE [lens] SET [qty] = @b+@c WHERE [id] = @a

@a is the id which user input in the textbox1
@b is an number user input in the textbox2
now @c should be the result of an query "select [qty] from [lens] where [id] = @a"

so ,the new value of [qty] will be the "old valus"+"valus in textbox2"

can someone tell me how can i do that?

[Frinavale]

Please review the following articles that outline how to use a database:
Database tutorial Part 1
Database tutorial Part 2

[Sandeep M]

You need to add the new value to existing value.. rite?

then use this query.

UPDATE [lens] SET [qty] = [qty]+@b WHERE [id] = @a