好正则

function EvaluatePassword(word)
{
    if (word == "")
    {
        return 0;
    }
    else if (word.length < 6)
    {
        return 1;
    }
    else
    {
        return word.match(/[a-z](?![^a-z]*[a-z])|[A-Z](?![^A-Z]*[A-Z])|\d(?![^\d]*\d)|[^a-zA-Z\d](?![a-zA-Z\d]*[^a-zA-Z\d])/g).length;
    }
}
var test = new Array("", "a1_", "abcdef","123456","112233","111111","aaaaaa","11111a","112233asd3", "abcde123", "ads23%", "aA1B2^&2");
for(var i in test)
{
    document.write(test[i] + " 的密码强度为" + EvaluatePassword(test[i]) + "<br>");
}