[Zope] can multiple users access gadfly database simultaneously ?

Hi, I have developed a product using Gadfly database. In that team members have to fill a form,and the data should go to their leaders database. My problem is more than one user can't enter simultaneously, also they can't submit the form together.How can i solve the problem.Can't multiple users access Gadfly database simultaneously ?. please help me. waiting for your quick reply thanks, bye, jacintha