jQuery - setting id from variable

i would like to create a html object with jquery and set the id from a variable but i don't know, how it could work.

This is the code:

        countArticle=eval("Count" + x+";");
        copy.css("width", "96px");
        copy.find("img").css("height", "50px");
        copy.append("Anzahl: <span class='count' id="countArticle" )>"+ 1
        +"</span>");
        copy.appendTo("#target").fadeIn();

Does anyone know, how this could work?

Thank you in advance! ;)