for | NN 2 IE 3 ECMA 1
This is a construction that allows repeated execution of statements, usually for a controlled number of times.
Example
    var userEntry = document.forms[0].entry.value;
    var oneChar;
    for (var i = 0; i < userEntry.length; i++) {
        oneChar = userEntry.charAt(i);
        if (oneChar < "0" || oneChar > "9") {
            alert("The entry must be numerals only.");
        }
    }