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An exception of type 'System.FormatException' occurred in mscorlib.dll but was not handled in user code   Additional information: Input string was not in a correct format.  /DATA ACCESS LAYER      public  DataSet StdCourseBindDAL( int  Uid)   {   SqlConnection con =  new  SqlConnection(constring);   con.Open();   SqlCommand cmd =  new  SqlCommand( "spGetRegCourses" , con);   cmd.CommandType = CommandType.StoredProcedure;   SqlDataAdapter sqlda =  new  SqlDataAdapter(cmd);   cmd.Parameters.Add( new  SqlParameter( "@UserID" , Uid));   DataSet ds =  new  DataSet();   sqlda.Fill(ds);   return  ds;   }      /BLL   public  DataSet StdCourseRegBindBLL( int  Uid)   {   return  da.StdCourseBindDAL(Uid);   }      /code behind   protected   void  Page_Load( object  sender, EventArgs e)   {   DataSet StudentDetails =  new  DataSet();   string  UName = Session[ "username" ].ToString();   StudentDetails = sbl.GetStudentDetailInLable(UName);   LblS_ID.Text = StudentDetails.Tables[0].Rows[0][ "StudentID" ].ToString() +  "" ;   LblS_Name.Text = StudentDetails.Tables[0].Rows[0][ "StudentName" ].ToString() +  "" ;   LblS_eMailID.Text = StudentDetails.Tables[0].Rows[0][ "EmailID" ].ToString() +  "" ;   LblPhnNum.Text = StudentDetails.Tables[0].Rows[0][ "PhnNo" ].ToString() +  "" ;   LblS_City.Text = StudentDetails.Tables[0].Rows[0][ "city" ].ToString() + "   ";   }   public   void  GridBindCourseStdReg( int  ID)   {   DataSet bda = sbl.StdCourseRegBindBLL(ID);   GrdCourseStdReg.DataSource = bda;   GrdCourseStdReg.DataBind();   }   protected   void  BtnCompCourses_Click( object  sender, EventArgs e)   {   int  UID;   UID =Convert.ToInt32(LblS_ID.Text);   GridBindCourseStdReg(UID);   }

Rajeesh Menoth · Answer

Hi,   Put a break point and check it again.

Ankit Sharma · Answer

Hi,   check the error location.if your input is in correct string format or not.

Vikas Gupta · Answer

Hello,   Use breakpoint on page load and check the value LblS_ID.Text may be null or blank.

Monica Priyadharshini · Answer

its fetching the value but its not assigning it to the variable UID, their it is throwing an exception

Monica Priyadharshini · Answer

LblS_ID   takes the value from the database using stored procedure

Rafnas T P · Answer

can you tell me what you entered in   LblS_ID text box

Rafnas T P · Answer

may you have entered space or character other than number in   LblS_ID   text box

Monica Priyadharshini · Answer

I have given in integer  bt its thowing an exception

Rafnas T P · Answer

or may be your  LblS_ID.Text value not able to convert to integer reason may be LblS_ID is empty or null

Rafnas T P · Answer

hi, check if user Id is string or integer