If you are looking for sample code to create connection record using WebAPI for Dynamics 365 CE, this post will help you. I am creating connection record for opportunity, you can change lookups entity based on your requirement. Hope it will help someone !!
Some time we need to calculate number of days between two dates in crm, we can easily do this using below JS script var d1=crmForm.all.FirstDate.DataValue; var d2=crmForm.all.SecondDate.DataValue; var DayValue=1000*60*60*24; alert(Math.ceil((d2.getTime()-d1.getTime())/DayValue)); Update for Dynamics 365 var d1=Xrm.Page.getAttribute(“FirstDate”).getValue(); var d2=Xrm.Page.getAttribute(“SecondDate”).getValue(); var DayValue=1000*60*60*24; alert(Math.ceil((d2.getTime()-d1.getTime())/DayValue));