How to get data from 3 tables based on asset no

Question

Hi friends, I have 3 tables 1)Issueproducts -- fields Emoid,Assetno,issueddate 2) ProductReturn Assetno,Returndate,Empid 3)producttransfer Fromempid,toempid,Assetno,Transfer date. Now if I searchby Assetno I want to diplay by joining 3 tables such that when an employee returned after that to whom that asset is issued,transfered. I tried with inner join but if one table doesn't have records the result is empty. Please help me.