HeadStart of java script

I am trying to learn javascript.there is some more exmaple, which can help for beginner in java script.In this first exmaple.We are creating an Html page.In this we are writing a funtion named

RandomNumber which will generate random number.I am taking sine from it and take the absolute value. This will get a number between 0 and 1.For every millisecond time changes and we got some unique number.In the script we use RandomNumber function.

In the second example I am writing code for email validation in java script for input text.User will enter email.If user will not entered ‘@’ in email address.Then it will give alert of invalid email address.