The Point table to replace all the content for the bonus field in the '99999'

The UPDATE Point SET bonus='9999'
The above is my writing is what is wrong, prompt content as follows:

[21000] [Microsoft] [11.0] SQL Server Native Client/SQL Server subquery return values of more than one, when the query to follow in=,!=, & lt; , & lt;=, & gt; , & gt;=, or the subquery is used as the expression, the situation is not allowed, (512)
[01000] [Microsoft] [11.0] SQL Server Native Client/SQL Server statement has been terminated, (3621)

What should I write,