Compare those 2 lines
cmd = new OleDbCommand("select user from tbl_blogs where book_name='" + txt2_bnm.text + "' ,con); `
// here is missing a double quote ^
...
cmd = new OleDbCommand("select blogs from tbl_blogs where book_name='" + txt2_bnm.Text + "' ", con);
[Update]
Quote:
but can you please give me another solution?
The problem is that the error I spotted prevent compilation of your code, this imply that you can't get this error message with this code.
So, as long as you don't show actual code and complete error message, no one can help you further.