Ajax call throwing 304 error in fireox

Question

$.ajax({

type: "POST",

url: ScriptVariables.Get('UrlLoadSkills'),

data: { job_did: ScriptVariables.Get('jobdid'), skill: myskills },

success: function (data) {

 

is there any error. its workiing in chrome but not in firefox. 

 i have tried with below two. but not working.

contentType: "application/json; charset=utf-8",

cache: true,