How can I target a span by its classname?

I want the innerHTML of some spans that do not have a unique ID but they do have unique Classes

I want to do something like var1 = document.getElementByCLASSNAME('')

edit:

I can't use Jquery, hell i cant even give开发者_如何学Python elements propper ID's. long story

document.getElementsByClassName = function(className)
{
    var hasClassName = new RegExp("(?:^|\\s)" + className + "(?:$|\\s)");
    var allElements = document.getElementsByTagName("*");
    var results = [];
    var element;
    for (var i = 0; (element = allElements[i]) != null; i++) {
        var elementClass = element.className;
        if (elementClass && elementClass.indexOf(className) != -1 
            && hasClassName.test(elementClass))
            results.push(element);
    }

    return results;
}

Based on this post on devshed: Get all elements of class 'abc'

There is a getElementsByClassName method (supported by the latest versions of major browsers) that returns a list of all elements with the specified class. Of course, many users still have older browsers, so a simpler solution is to use a library such as jQuery and select elements with $('.someclass').

Using getElementsByClassName may cause problems with versions of IE. querySelectorAll should be more widely compatible. i.e. document.querySelectorAll('.my-class') or document.querySelectorAll('div.my-class')