Trouble writing If-Statements :     //main code\\
    <html>

    <head>
        <script language="javascript" type="text/javascript" src="codeChallenge3.js"></script>
    </head>

    <body>

    <head>CONDITIONALS CODE </head>
    <p></p>
    <hr/>
    <h2>Task #1</h2>
    <script>
        //#2
        var phoneNum = "555-5555";
        document.write("Check the following phone number: ", phoneNum, " = ", validPhone(phoneNum));
    </script>
    </body>

    </html>
     //function\\
    function validPhone(phoneNum)
    var 
    if () {
    return "True"
    }
    else() {
    return "False";
    }

I have trouble writing if statements so can someone help me by giving me hints to determine if a number is a valid home phone number (without area code)