Password Length Validation using Javascript



Source code:
<input type="text" id="txtPassword" onkeyup="CheckPasswordStrength(this.value)" /> <span id="password_strength"></span> <script type="text/javascript"> function CheckPasswordStrength(password) { var password_strength = document.getElementById("password_strength"); //TextBox left blank. if (password.length == 0) { password_strength.innerHTML = ""; return; } //Regular Expressions. var regex = new Array(); regex.push("[A-Z]"); //Uppercase Alphabet. regex.push("[a-z]"); //Lowercase Alphabet. regex.push("[0-9]"); //Digit. regex.push("[$@$!%*#?&]"); //Special Character. var passed = 0; //Validate for each Regular Expression. for (var i = 0; i < regex.length; i++) { if (new RegExp(regex[i]).test(password)) { passed++; } } //Validate for length of Password. if (passed > 2 && password.length > 8) { passed++; } //Display status. var color = ""; var strength = ""; switch (passed) { case 0: case 1: strength = "Weak"; color = "red"; break; case 2: strength = "Good"; color = "darkorange"; break; case 3: case 4: strength = "Strong"; color = "green"; break; case 5: strength = "Very Strong"; color = "darkgreen"; break; } password_strength.innerHTML = strength; password_strength.style.color = color; } </script>