input有值时button可点无值时button不可点击

<input name="title" class="form-control" onkeyup="checkContent(this)" type="text" id="phone" placeholder="请输入手机号">
<input name="title" class="form-control" onkeyup="checkContent(this)" type="text" id="deviceNumber" placeholder="请输入手机设备号">




function checkContent(obj) {
	 if($(obj).val() === '' ||$(obj).val() === null){
		   if($("#deviceNumber").val() !== ''||$("#phone").val() !== '' ){
			   $('#addOneBtn').attr('disabled',false);
		   }else{
			   $('#addOneBtn').attr('disabled',true);
		   }
	   }else{
		   $('#addOneBtn').attr('disabled',false);
	   }
}