Extjs中在textfield、numberfield等后面加几个文字

{
									xtype : "numberfield",
									anchor : "70%",
									fieldLabel : "综合平均电价",
									name : "elePrice",
									allowNegative : false,
									allowBlank : true,
									listeners : {
										render : function(obj) {
											var font = document.createElement("font");
											font.setAttribute("color","black");
											var redStar = document.createTextNode('元/kW.h');
											font.appendChild(redStar);
											obj.el.dom.parentNode.appendChild(font);
										}
									}
								}