select statement

Hi Friends,

suppose i have 6 fields f1,f2,f3,f4 & f5, f6.

Now i wrote the select statement.

I wanted to write the logic for field f6. If f6 is blank then it will exclude the records from the report.

My selection is based on 2 fields criteria so that it will select other values i.e

select f1 f2 f3 f4 from table where f5 = '1' and not f6 is initial.

Is the above select statement is correct??

Plz send me the coding.