hi how can i make a script that when i have 2 fields and when filled b is bigger then filed a it will give an err massage and then it will go to that filed

I think I would:

If[sign(Date2-Date1)+1]

...since both 1 and 2 is translated into true!

--sd

i'm new here

how do i put the script on the filed, then when u fill it it will run the script?

Well, perhaps in other tools, but filemaker Inc., has due to it's spreadsheet'ish notion or carry over of a field type not found elsewhere in the database world - calculation fields - decided against the provision event triggers in the strictest sense.

Instead could under a field stuff in the above or other calc's so make something to that would force some sort of re-rendering thru.

These native validations however, is often rejected by the developers for not giving the solution a real professional touch and feel, due to limited customizations posible with the actual dialog they produce.

My take they're not uttely daft, to use - since the rollback is impeccable... something you have to spend a long time to establish if you insist on scripted validations only. You need to have a log of the alterations of each field have undergone, plus if a rollback is required, a scripted digestion of this logging.

Event trigger plugins seems then to be the solution, but you need to know when ever a screen rendering is occuring to prevent false triggings ... at other times is triggings missing because the calc' is hanging.

Well I wouldn't use such plugins, and might have sounded too cautious in this post. I would always endorse native validations over scripted, unless a scripting was called anyway from a button found on the layout - but you milage could be different so the more things you could delegate to obviously pretty reliant blackboxes the better - then download a few and give them a try.

Some kind of damage control do I believe is to stuff the call's to the event trigger inside the native validation that then is bypassed by always being true ... but it doesn't releive you from the burden of designing the rollback.

I see you're a mac user as well, then wouldn't you be a stranger to HUI's demand to make matters regrettable to the users:

http://developer.apple.com/documentation/UserExperience/Conceptual/OSXHIGuidelines/XHIGHIDesign/chapter_5_section_2.html#//apple_ref/doc/uid/TP30000353-TPXREF107

(here click at "Forgiveness")

http://www.joelonsoftware.com/uibook/chapters/fog0000000062.html

--sd