How it is possible, if it is?
Do you mean the two should happen at the same time, or one after another?
If you want to have the walking and speaking at the same time, you could do this:
Make an animation of a character walking and talking at the same time. Use the 'SetCharacterView' to change the character's normal walking view to the 'walking and talking' view. Then use the 'DisplaySpeechBackground' function. Your script should look something like this:
SetCharacterView (EGO, 15);
MoveCharacter (EGO, 250, 150);
DisplaySpeechBackground (EGO, "Hello, world!");
while (character[EGO].walking) Wait (1);
ReleaseCharacterView (EGO);
You can use the RemoveOverlay to remove the background text. The overlay ID is returned by the command.
Correct me if I'm wrong. I just made this off of the top of my head.
I've tried that sort of stuff myself before, giving up miserably. Geoffkhan's idea looks pretty good, though, so long as you don't mind losing cntrol of the main character while the "wait" function is taking place.
I have not tried that yet, but ... thanks ^_^