Validating Password in all Way using JavaScript

<html>
    <head>
        <title>Password validation</title>
        <script language="javascript">
function CheckPassword()
{
    var pw = pass.pw.value;
    var cpw = pass.cpw.value;
    if (pw != cpw) window.alert("Re-enter your password");
    if (pw.length == 0)
    {
        alert("Please enter your password");
    }
    else if (pw.length < 3)
    {
        alert("Please enter aleast 3 characters password");
    }
    else if (pw == /^[A-Za-z]\w/)
    {
        alert("Your password first character must be a letter");
    }
    else if (pw == /^(?=.*[A-Z])/)
    {
        alert("Your password must contain atleast one uppercase letter");
    }
    else if (pw == /^(?=.*[a-z])/)
    {
        alert("Your password must contain atleast one uppercase letter");
    }
    else if (pw == /^(?=.*[0-9])/)
    {
        alert("Your password must contain atleast one numeric digit");
    }
    else if (pw == /^(?!.*\s)/)
    {
        alert("Your password must contain atleast one special character");
    }
    else window.alert("Your password is matched");
}

        </script>
    </head>
    <center>
        <body font size=5 bgcolor="lightgreen" leftmargin=50 topmargin=50 >
            <Form id="pass" onSubmit="CheckPassword(this)" >
PASSWORD:


                <input type=password name="pw"size=10 max length=8 ></input>
                <br>
                    <br>
CONFIRM PASSWORD

                        <input type=password name="cpw"size=10 max length=8 ></input>
                        <br>
                            <br>
                                <br>
                                    <input type="submit" name="sub" value="submit">

                                        <input type="reset" name="rt" value="reset">
                                        </center>
                                    </body>
                                </html>