Retrieve Case Origin option set in case entity :
function GetCaseOriginCode()
{
var OptionSetControl = Xrm.Page.getAttribute("caseorigincode");
for(var intCounter=0; OptionSetControl.getOptions().length; intCounter++){
alert(OptionSetControl.getOptions()[intCounter].text);
alert(OptionSetControl.getOptions()[intCounter].value)
}
}