How to define undo.isValid?

[Johnwhite]

Hi experts,

if my script like this

app.activeDocument.undo();

for undo activeDocument last changed

but if it is nothing to undo it will give me an error;

how can make the script something like

if (app.activeDocument.undo.isValid)
{app.activeDocument.undo();}

???

thanks

regard

John

[Manan Joshi · Accepted solution]

Hi John,

Try the following

if(app.activeDocument.undoHistory.length)
    app.activeDocument.undo();

-Manan

[Johnwhite]

thank you Man,

thank so much.

John