System.Data.SqlClient.SqlException: Syntax Error Converting The Varchar Value 'V' To A Column Of Data Type Int

 
I am using  a stored procedure which returns a value of charecter datatype 'V' to the calling program.I am getting an sql exception 
System.Data.SqlClient.SqlException: Syntax error converting the varchar value 'V' to a column of data type int
i didnot define any int datatype in my table
this is my code
SqlCommand com = new SqlCommand("StoredProcedure4", connection);
com.CommandType = CommandType.StoredProcedure;
 
 
SqlParameter p1 = com.Parameters.Add("@uname", SqlDbType.NVarChar);
SqlParameter p2 = com.Parameters.Add("@opwd", SqlDbType.NVarChar);
SqlParameter p3 = com.Parameters.Add("@role", SqlDbType.NVarChar);
p3.Direction = ParameterDirection.ReturnValue;
p1.Value = username.Text.Trim();
p2.Value = password.Text.Trim();
com.ExecuteReader();
lblerror2.Text = (string)(com.Parameters["@role"].Value);
can your figure out what is the error ? Is it a coding error or error of the databse