<ul>
<li>
<input type="radio" name="radio" value=" The front desk to pay  " id="radio" /> The front desk to pay   If you want to keep the room overnight, please pay in advance.
</li>
<li>
<input type="radio" name="radio" value=" Guarantee payment " id="radio" /> Guarantee payment   -- the customer service staff will call you later.
 And confirm the information required for the warranty.
</li>
</ul>

var chkObjs=null;

var obj=document.getElementsByName("radio")
for (var i=0;i<obj.length;i++){ //Traverse the Radio
if(obj[i].checked){
chkObjs=obj[i].value;
}
}
alert(chkObjs);