how to validate a telephone number in multiple format

Question

i have a telephone textbox. which has two format.

one is 1 800 ###-#### and 800 ###-####.i have made regular expressions for 1 800 ###-#### and it is working fine

but unable to validate both format.means telephone number can support both format .my regular expression for 1 800 ###-#### is 

 "^\1[\s](800)?[\s\-]?\d{3}\-?\d{4}$"  but unable to make both.please help me.what is the regular expressions for support two format