Forum Post: RE: get value from parent form using javascript

You could always retrieve it through the REST endpoint:

function GetAllotmentType() {     var serverUrl = Xrm.Page.context.getClientUrl();     var oDataSelect = serverUrl + "/XRMServices/2011/OrganizationData.svc/ContractDetailSet?$select=ContractId,contract_line_items/AllotmentTypeCode&$expand=contract_line_items&$filter=ContractDetailId eq guid'" + Xrm.Page.data.entity.getId() + "'";      var retrieveReq = new XMLHttpRequest();     retrieveReq.open("GET", oDataSelect, false);     retrieveReq.setRequestHeader("Accept", "application/json");     retrieveReq.setRequestHeader("Content-Type", "application/json;charset=utf-8");     retrieveReq.onreadystatechange = function () {         GetContractData(this);     };     retrieveReq.send(); }  function GetContractData(retrieveReq) {     if (retrieveReq.readyState == 4) {         if (retrieveReq.status == 200) {             var retrieved = JSON.parse(retrieveReq.responseText).d;             var x = retrieved.results[0].contract_line_items.AllotmentTypeCode.Value;             alert(x);         }     } }