正则判断数字

var platform = $("#from_platform").val();
var reg = /^[1-9]\d*$|^0$/;
 if (reg.test(platform)) {
var advertiser_id = $("#advertiser_id").val()
 if (platform != advertiser_id) {
layer.msg("If 'From platform' is number ,then it must be the same with 'id'!", {
shade: 0.7,
icon: 5,
time: 2500
})

 return false
 }
 }