Hello Narendra, i got the same issue while writing a variable to a textbox. if you are having the issue while writing. then this solution might help you ...there might be two root cause of it 1)...sometimes the textbox can take values upto specific number (let us consider a text box can contain only 35 characters and if you are writing more then 35 character then the above error might occur..... 2) also if you are trying to write a comma(,) or any special character which that textbox won't allow it to write then it might throw an exception.... i hope this can help you....