how to find datagrid cell value using javascript?

Question

hi friends,

   i write again my previous question because still i am not getting answer.  please give a sample code for when i select checkbox in datagrid, that row cell(1) value is displayed in textbox(this textbox is outside of the datagrid).
         and uncheck the checkbox that row cell(1) value removed from textbox. please give a sample javascript code.

Thanks