If you're using an ID test, you can do this.

document.getElementById(test)

        .getElementsByTagName(img)[0].style.display=block;

This uses getElementsByTagName which returns a collection of the images found. The [0] grabs the image at index 0 (the first image), and then applies the style.

If you have a class test, you can do this, but it won't work in IE7 and below:

var imgs = document.querySelectorAll(.test > img);



for( var i = 0; i < imgs.length; i++ ) {

    imgs[i].style.display=block;

}

For the widest browser compatibility, you can do this:

function getElementsByClassName( root, clss ) {

    var elems = document.getElementsByTagName('*'),

        result;

    clss =   + clss +  ;

    for( var i = 0; i < elems.length; i++ ) {

        if( (  + elems[ i ].className +  ).indexOf( clss ) > -1 ) {

            result.push( elems[i] );

        }

    }

    return result;

}



var tests = getElementsByClassName( document, test );



for( var i = 0; i < tests.length; i++ ) {

    var img = tests[i].getElementsByTagName('img')[0];

    if( img ) {

         img.style.display=block;

    }

}