I do not understand something
i set it to numbers only WebTextField

way accept alphabetic character

I think it’s a clue to mobile devices to the type of keyboard shown, not a validation of the input text itself.

Correct, Wayne.

Any sufficiently HTML5 compliant browser will enforce it. I know Safari does, and I think IE10 also (based on reports from my users). Safari doesn’t filter the characters, it just rejects the entire field once you accept or move off of the field.

From the LR entry on WebTextField:

The Type property implements concepts from HTML5. Browsers that fully support these new concepts support the Type property fully. Mobile Safari supports these concepts fully. Safari and Google Chrome only treat the Number type uniquely and all other browsers treat them all the same.