Searching for numbers in a string

Question

I am trying to filter passwords stored in a string variable and ensure that they contain at least a number and one capital letter.
how do you search for numbers in a string and search if that string contains a character in uppercase?

Answer 1

function checkString(username){
var userfield = username;
var valid = '0123456789ABCDEFGHIJKLMN�OPQRSTUVWXYZ'; // define valid characters
if(!isValid(userfield.value,valid)){
alert("Invalid user name format");
userfield.value="";
userfield.select();
     userfield.focus();
}else{
err = 0;
userfield = userfield.value;
function isValid(string,allowed) {
for (var i=0; i< string.length; i++) {
if (allowed.indexOf(string.charAt(i)) == -1)
return false;
return true;
}