Why would you want to do this? Not sure but a sample here:

[as]var _x = 100;

function a() : void
{
trace(“\t\tCalled from A = _x” + _x + “\n”);

}

var b = function (): void
{
trace(“\t\tCalled from B \n”);
}

trace(“Do a regular B call\n”);
b();

trace(“Convert B to A\n”);
b = a;

trace(“B Converted\n”);
b();
trace(“Do a regular A call\n”);
a();[/as]

Result

[as]Do a regular B call

Called from B

Convert B to A

B Converted

Called from A = _x100

Do a regular A call

Called from A = _x100[/as]