ASP.Net Int32.Parse Error: input string was not in a correct format

akhter says:

int lbpk = Int32.Parse(lbitpqty.Text);

lbitpqty.Text value is empty. So you are getting the error.

You need to check when lbitpqty.Text is empty then set the lbpk to zero.

Use below code.

int lbpk = !string.IsNullOrEmpty(lbitpqty.Text) ? Int32.Parse(lbitpqty.Text) : 0;