Password strength checker I would like to receive feedback about my code.  Is there any better way to shorten the code or is it fine?

Demo

var pass_strength;
function IsEnoughLength(str,length){
    if ((str == null) || isNaN(length))
        return false;
    else if (str.length &lt; length)
        return false;
    return true;
}
function HasMixedCase(passwd){
    if(passwd.match(/([a-z].*[A-Z])|([A-Z].*[a-z])/))
        if ( passwd.split(/[a-z]/).length &gt;= 3 &amp;&amp; passwd.split(/[A-Z]/).length &gt;= 3)
            return true;
        else
            return false;
    else
        return false;
}
function HasNumeral(passwd){
    if(passwd.match(/[0-9]/))
        return true;
    else
        return false;
}
function HasSpecialChars(passwd){
    if(passwd.match(/.[!,@,#,$,%,^,&amp;,*,?,_,~]/))
        return true;
    else
        return false;
}
function CheckPasswordStrength(pwd)
{
    if (IsEnoughLength(pwd,14) &amp;&amp; HasMixedCase(pwd) &amp;&amp; HasNumeral(pwd) &amp;&amp; HasSpecialChars(pwd))
        pass_strength = "&lt;b&gt;&lt;font style='color:olive'&gt;Very strong&lt;/font&gt;&lt;/b&gt;";
    else if (IsEnoughLength(pwd,10) &amp;&amp; HasMixedCase(pwd) &amp;&amp; HasNumeral(pwd) &amp;&amp; HasSpecialChars(pwd))
        pass_strength = "&lt;b&gt;&lt;font style='color:Blue'&gt;Strong&lt;/font&gt;&lt;/b&gt;";
    else if (IsEnoughLength(pwd,10) &amp;&amp; HasMixedCase(pwd) &amp;&amp; HasNumeral(pwd))
        pass_strength = "&lt;b&gt;&lt;font style='color:Green'&gt;Medium&lt;/font&gt;&lt;/b&gt;";
    else
        pass_strength = "&lt;b&gt;&lt;font style='color:red'&gt;Weak&lt;/font&gt;&lt;/b&gt;";
    document.getElementById('pwd_strength').innerHTML = "Password strength: " + pass_strength;
}
You can replace all of the 

if(x.match(...))
    return true;
else
    return false;


with:

return x.match(...) !== null;


or if you're content with returning a truthy/falsy value instead of proper booleans you can even simplify it to: 

return x.match(...)

IsEnoughLength is ungrammatical. I'd use IsLongEnough
You're mixing the password strength estimation with presentation logic. You should have one function which returns a value indicating the strength of the password and another which manipulates the DOM.
Use CSS classes to format the text instead of &lt;b&gt; and &lt;font style=
Personally I wouldn't bother with argument checking in such a simple internal function. But if you do, throw an exception on programmer error, don't just return false.

if ((str == null) || isNaN(length))
    return false;


should be something like

if (str == null)
    throw new Error("str must not be null");
if(isNaN(length))
    throw new Error("length must be a number");


(or a fancier exception class if you want)