Create TRIGGER Remove White Spaces From A Fields In Table-scan And Fix

hi
i have table i use it for update insert
and the users use this table from a grid on the web
and i need to prevent from white space in the fields in table
so how to
create TRIGGER remove white space from a fields in table scan and fix it ?





Code Snippet
SELECT TRIM(fieldname)
, LTRIM(fieldname)
, RTRIM(fieldname)
, LTRIM(RTRIM(fieldname))
FROM tablename





Code Snippet
WHERE (LTRIM(RTRIM(fieldname)) = 'Approve')




Code Snippet
replace(@text,' ','')







create TRIGGER on update insert and not to damage the text in the all fields
TNX