One Way Drag and Drop

How can I implement one way drag and drop? In other words, I only want to be able to drag from grid A, and drop into grid B (not the other way around)?



Thanks.

dhtmlx.com/dhxdocs/doku.php?id=d … g_and_drop


gridB.attachEvent(“onBeforeDrag”,function(id){
return false;
}
gridA.attachEvent(“onDragIn”,function(id){
return false;
}