Datareport textbox change event

Hi,
We are doing some reporting using VB6 datareport. I have set cangrow property of some rpttextbox true and i have used lines between rpttextbox fields. My problem is line dont have cangrow property, so it will not grow if rpttextbox grow. If there is any event triggering when rpttextbox changes, i can use that to get rpttextbox hieght and can assign that to rptline. So is there any events i can use?? Or is there any other way to make lines have same hieght as rpttextbox ?? please help
Thank you