jquery 实现按钮点了之后,没有返回前,不能继续点击

$(function(){
        var _dbservice= $("input[name='dbservice']");
        var _dbip= $("input[name='dbip']");
	var _dbuser= $("input[name='dbuser']");
	var _dbpass= $("input[name='dbpass']");
	var _customsql= $("#customsql");
	var _exportname= $("input[name='exportname']");
        var _ip_bt = $(".content .con #condition .es_1");
           console.log(_customsql);
        _ip_bt.on('click',function(){
                _ip_bt.attr('disabled','disabled'); 
                var data={};
                data.dbservice=_dbservice.val();
                data.dbip=_dbip.val();
                data.dbuser=_dbuser.val();
                data.dbpass=_dbpass.val();
                data.customsql=_customsql.val();
                data.exportname=_exportname.val();
                var successfn = function(jdata){
                _ip_bt.removeAttr('disabled');
                $(".gridtable").empty();
                var _HTML="<tr><th>DownLoad Url </th></tr>";
                 _HTML=_HTML+"<tr><td>"+jdata+"</td></tr>";
                $(".gridtable").html(_HTML); 
                };
                var errorfn = function(){
                _ip_bt.removeAttr('disabled');
                alert("数据获取出错");
                };
                $.ajax({
				type: "get",
				data: data,
				url: "/api/exportcustomdata",
				dataType: "text",
				success: function(d){
					successfn(d);
				},
				error: function(e){
					errorfn(e);
				}
			});
        });
	}
)