String or binary data would be truncated. The statement has been terminated.How to handle this error?

I am getting this error when ever i click the register button. I am also not putting more values than assigned in the table.The table is below:
FirstName              nvarchar(50)       Allow Nulls
LastName              nvarchar(50)       Allow Nulls
Email                     nvarchar(50)        Allow Nulls
Password              nvarchar(50)        Allow Nulls
Address                 nvarchar(50)       Allow Nulls
...