Forms not recognising errors

[london airsports]

I have set up a new contact form with each field requiring information to be filled in before submitting; however, even a blank form is accepted and the success page is returned when I test it.
How can I ensure that forms which have no information are returned with an error message?
Help appreciated...
D

[london airsports]

Found the error....
my form name had spaces in the name; now the form name has no spaces and it works.
D.