$("#insertMsg").on("click",function(){　　//获取下拉选项框的值    var textFeildValue = $("#text_type").find("option:selected").text();    //获取textarea的值        var myField=document.getElementById("text_smsnr");    if (document.selection) {
   //IE浏览器           myField.focus();           sel = document.selection.createRange();           sel.text = "{"+textFeildValue+"}";           sel.select();     }else if (myField.selectionStart || myField.selectionStart == '0'){
   //火狐/网景 浏览器       //得到光标前的位置       var startPos = myField.selectionStart;       //得到光标后的位置       var endPos = myField.selectionEnd;       // 在加入数据之前获得滚动条的高度       var restoreTop = myField.scrollTop;       myField.value = myField.value.substring(0, startPos) + "{" + textFeildValue +"}" + myField.value.substring(endPos, myField.value.length);       //如果滚动条高度大于0       if (restoreTop > 0) {         // 返回         myField.scrollTop = restoreTop;       }//                   myField.focus();       myField.selectionStart = startPos + "{"+textFeildValue.length+"}";       myField.selectionEnd = startPos + textFeildValue.length;     }     else {       myField.value += "{"+textFeildValue+"}";//                   myField.focus();     }})