PHP/JavaScript Regular expression for email validation

 following expression validates email address:

^[a-zA-Z0-9.-_]+[@]{1,1}[a-z]+[.]{1,1}[a-z]{2,4}$

PHP/Javascript Phone number validation

following regular expression accepts phone number in any form that user can supply it:
yyyyyyyyy
yyy yyyyyy
yyy yyy yyy
xxxyyyyyyyyy
xxx yyyyyyyyy
xxx yyy yyyyyy
xxx yyy yyy yyy

+xxxyyyyyyyyy
+xxx yyyyyyyyy
+xxx yyy yyyyyy
+xxx yyy yyy yyy

so here is regular expression:

^[+]{0,1}[0-9]{0,3}[ ]{0,1}[0-9]{3,3}[ ]{0,1}[0-9]{3,3}[ ]{0,1}[0-9]{3,3}$

works in PHP, Javasrcipt and i suppose anywhere else