function checkNum(obj) {	    obj.value = http://www.mamicode.com/obj.value.replace(/[^/d.]/g,""); //清除“数字”和“.”以外的字符  	    obj.value = http://www.mamicode.com/obj.value.replace(/^/g,""); //验证第一个字符是数字而不是. 	    obj.value = http://www.mamicode.com/obj.value.replace(/.{2,}/g,"."); //只保留第一个. 清除多余的.   	    obj.value = http://www.mamicode.com/obj.value.replace(".", "$#$").replace(/\./g, "").replace("$#$", ".");	    if(obj.value =http://www.mamicode.com/=  undefined || obj.value==null || obj.value=="")	    {	    	obj.value="http://www.mamicode.com/0.0";	    }	    var tempStr = new String(obj.value);	    if(tempStr.indexOf(‘.‘) != tempStr.length-1)	    {	    	var valss = parseFloat(obj.value);	    	obj.value = http://www.mamicode.com/Math.round(valss*100)/100;>