Textbox under gridview in where condition

Question

Hi,
  i gave a gridview with textbox in first row and first column after entering one data in thid textbox corresponding data should fetch from DB and display 2nd and 3ed column of first row. next if i enter data in 2nd row and first column textbox the corresponding data should fetch from DB and display in 2nd and 3ed column of 2nd row and so on. how to do this. Here my problem is how to mention textbox inside the gridview while writing query mainly in where condition.
like select * from employee where id='"+textbox1.text+"'

here i used textbox inside the grid, in this condition how to mention textbox under where condition. please can anyone help me? it's very urgent please.