regex - How to check on initials with html pattern? -

i'm making database can insert customers.

by initials of every forename want check if it's in right order. want as: "t.l.r." dots between every initial.

to check this, want use pattern.

what got this:

<input required="true" type="text" required pattern="[a-za-z]{1}+\.[a-za-z]{1}+\.[a-za-z]{1}+\.">

this code doesn't anything. know answer?

thanx in advance!

you combining {1} means 1, , + means 1 or more. not work.

try this:

[a-za-z]\.[a-za-z]\.[a-za-z]\.

since [] default means 1, can drop {1}

this mean need 3 characters in initials, i.k. not count.

if want use 1 character, followed dot, , repeated can use this:

([a-za-z]\.)+

also, don't forget add prefix ^ postfix $ match whole string:

^([a-za-z]\.)+$

Ben