My code that I tried is as follows:
var dataO = new Object(); dataO.numberId = 1; dataO.companyId = 531; $.ajax({ type: \"POST\", url: \"TelephoneNumbers.
Is not necessary to pass the data as JSON string, you can pass the object directly, without defining contentType or dataType, like this:
contentType
dataType
$.ajax({ type: "POST", url: "TelephoneNumbers.aspx/DeleteNumber", data: data0, success: function(data) { alert('Done'); } });