var aBlocks = new Array('step2a','step2b','step2c','step2d','step2e');
 function showBlock(idBlock) {
    for(i = 0; i < aBlocks.length; i++){
        if(aBlocks[i] == idBlock) {
            jQ('#'+idBlock).show('slow');
        } else {
            jQ('#'+aBlocks[i]).hide();
        }
    }
 }