div.sceditor-container iframe, div.sceditor-container textarea {  background: transparent;}.postbg {  background-position: 0 0; background-repeat: repeat;}

$(function() {  $("div.postbody").each(function() {    var n = this;    if($(".post-entry", n).length) {      n = $(".post-entry", n)[0]    }else {      if($(".content", n).length) {        n = $(".content", n)[0]      }    }    while(n.nodeType != 3 && n.hasChildNodes()) {      n = n.childNodes[0]    }    if(n.nodeType != 3) {      return;    }    if(n.nodeValue.substr(0,8)  != "[postbg=") {      return;    }    var m = n.nodeValue.match(/^\[postbg=([^\]]*)\]/);    if(!m) return;    $(this).closest("div.post-container,div.post,td.row1,td.row2,div.postmain").addClass("postbg").css("background-image", "url(" + m[1] + ")");    n.nodeValue = n.nodeValue.replace(/^\[postbg=[^\[]*\]\n?/, "");    if(!n.nodeValue && n.nextSibling && n.nextSibling.nodeType == 1 && n.nextSibling.tagName == "BR") {      $(n.nextSibling).remove()    }  });  if($("#text_editor_textarea").length && $.sceditor) {    var bglist = "http://i.imgur.com/20aRJFn.png,http://i.imgur.com/DcTM2Ng.jpg,http://i.imgur.com/tkC3deY.jpg,http://i.imgur.com/pfTcnqF.png,http://i.imgur.com/dAQtdaR.gif,http://i.imgur.com/48CU2Qx.png,http://i.imgur.com/lRuwoVi.png,http://i.imgur.com/EHp45H1.png,http://i.imgur.com/8bhbqFF.png,http://i.imgur.com/tb80sYG.png,http://i.imgur.com/6LPhzcp.png,http://i.imgur.com/DkRuYf1.png,http://i.imgur.com/57F0z86.jpg,http://i.imgur.com/PZyMuXF.png".split(",");    var bgnum = -1;    var val = $("#text_editor_textarea").val();    if(val.substr(0,8)  == "[postbg=") {      var m = val.match(/^\[postbg=([^\]]*)\]/);      if(m) {        var r = $.inArray(m[1], bglist);        if(r != -1) {          bgnum = r        }else {          bgnum = bglist.length - 1        }        $(function() {          $(".sceditor-container").css("background-position", "0 " + ($(".sceditor-toolbar").height() + 6) + "px");          $(".sceditor-container").css("background-image", "url(" + m[1] + ")")        });        $("#text_editor_textarea").val(val.replace(/^\[postbg=[^\[]*\]/, ""))      }    }    $(function() {      if(!$("#text_editor_textarea").sceditor("instance")) {        return      }      $('<a class="sceditor-button" unselectable="on" title="Background of message"><div unselectable="on" style="background:url(http://i.imgur.com/Hrf5w1i.gif);opacity:1">Background of message</div></a>').insertAfter(".sceditor-button-fahide").click(function(e) {        if(e.ctrlKey) {          $(".sceditor-container").css("background-image", "");          bgnum = -1        }else {          bgnum++;          if(!bgnum) {            $(".sceditor-container").css("background-position", "0 " + ($(".sceditor-toolbar").height() + 6) + "px")          }          $(".sceditor-container").css("background-image", "url(" + bglist[bgnum % bglist.length] + ")")        }      })    });    $(function() {      $('form[name="post"]').submit(function() {        if(bgnum != -1) {          $("#text_editor_textarea").val(function(i, val) {            return"[postbg=" + bglist[bgnum % bglist.length] + "]" + val          })        }      })    })  }});

http://i.imgur.com/20aRJFn.png,http://i.imgur.com/DcTM2Ng.jpg,http://i.imgur.com/tkC3deY.jpg,http://i.imgur.com/pfTcnqF.png,http://i.imgur.com/dAQtdaR.gif,http://i.imgur.com/48CU2Qx.png,http://i.imgur.com/lRuwoVi.png,http://i.imgur.com/EHp45H1.png,http://i.imgur.com/8bhbqFF.png,http://i.imgur.com/tb80sYG.png,http://i.imgur.com/6LPhzcp.png,http://i.imgur.com/DkRuYf1.png,http://i.imgur.com/57F0z86.jpg,http://i.imgur.com/PZyMuXF.png