Trim.js

function trim(inputString) {
    // Removes leading and trailing spaces from the passed string. Also removes
    // consecutive spaces and replaces it with one space. If something besides
    // a string is passed in (null, custom object, etc.) then return the input.

    if (typeof inputString != "string") {
        return inputString;
    }
    var retValue = inputString;

    // Check for spaces at the beginning of the string
    var ch = retValue.substring(0, 1);
    while (ch == " ") {
        retValue = retValue.substring(1, retValue.length);
        ch = retValue.substring(0, 1);
    }
    // Check for spaces at the end of the string
    ch = retValue.substring(retValue.length - 1, retValue.length);
    while (ch == " ") {
        retValue = retValue.substring(0, retValue.length - 1);
        ch = retValue.substring(retValue.length - 1, retValue.length);
    }

    // Note that there are two spaces in the string - look for multiple spaces within the string
    while (retValue.indexOf("  ") != -1) {
        retValue = retValue.substring(0, retValue.indexOf("  ")) +
            retValue.substring(retValue.indexOf("  ") + 1, retValue.length);
        // Again, there are two spaces in each of the strings
    }
    return retValue; // Return the trimmed string back to the user
}