Help! Well i was working on my project and i got stucked

Question

i was trying to build program like
when you click on button, background of a "demo" changes to red;
and when you click again then the background clolor of "demo" changes basck to its own color define by usert;
well i have tried with "checkbox " and it worked but i was not success with "button"

here is example :

https://code.sololearn.com/W256nCYOPj7R/?ref=app

Answer 1

You mean this ?
https://code.sololearn.com/WDf9cT41gj6i/?ref=app

Answer 2

yes yes yes than k yuo very much @Swapnil .
I soloute for your great help for mee
thnx again 😁😁😁😁👍👍👍👍👍👍👍👍