Ajax request jquery - ajax

Question

Need
Pull PlanId from the Get variable send it to Web Service and I have GetPlanInfo function
Get the details of the package and display them
var MainServiceURL = 'http://someWebService';
var plan=[];
function planInit()
{
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
dataType: "json",
url: MainServiceURL + "/GetPlanInfo",
data: {"ID" : ID ,"countryID" : CountryID},
success: function(response) {
plan = response.d;
main();
}
});
}
function main(plan)
{
document.getElementById("costPerMonth").innerHTML = plan.CostPerMonth;
document.getElementById("firstMonthPrice").innerHTML = plan.FirstMonthPrice;
document.getElementById("planName").innerHTML = plan.Name;
document.getElementById("landline").innerHTML = plan.Landline;
document.getElementById("mobile").innerHTML = plan.Mobile;
}
Where error?

Answer 1

Within the function main you treat a plan variable like a known object and you try to access its properties. However, plan is only an argument for the function main, which you don't pass once you get the response from your request. Look at:
success: function(response) {
plan = response.d;
main();
}
When you write like this, you call main function without passing plan argument. It should look like:
success: function(response) {
plan = JSON.parse(response).d;
main(plan);
}
Because as a response you only get a string - you have to translate it to JSON object using JSON.parse function.