JavaScript Program to Check Whether String Containg letters 'a' and 'c' Using Regular Expression

Write a JavaScript program to check whether string containg letters 'a' and 'c' using regular expression.

Source Code
    <title>Regular expression - Checking given letters</title>
    <script language="javascript">
        var input = prompt('Enter some text')
        re = /[ac]/
            alert('The string contains letter a or c or both')
            alert('String does not contain a or c or both')