Constructing an sql string

[davebat]

Hi, Im trying to build some sql through string concatenation can someone take a look, im having problems with quotes.

set @SQL = @SQL + 'CASE owner_ein '
set @SQL = @SQL + 'WHEN ''NA'' THEN ''Unassigned'' '
set @SQL = @SQL + 'else ''''<a target=''_blank'' href=''http://url?ein='' + ein + ''''>'' + LEFT(firstname, 1) + ''. '' + surname + ''</a>'' AS name''' 
set @SQL = @SQL + 'END as name '

Its the third line im having trouble with.