1) Create a new stack at your chosen mobile device size

2) Drag on a button and call it "Call"

3) Drag on a field and call it "number"

Add this code to the call button

on mouseUp
	launch url "tel:" && field "number"
	put the result into field "number"
end mouseUp

The launch URL functionality found in LiveCode has been extended to interface directly with mobile devices. To start a telephone call we simply pass the following string to the launch URL command:

tel: [Phone number]

So, to make a call to the LiveCode support line you would use the following:

tel:+448452198923

Our final line of code would look like this:

launch url "tel:+448452198923"

In this example we are letting the user enter the phone number into the field we dragged onto our stack. We build the call string and pass it to the launch command. The second line of code simply puts the result of our call into the same field. If the string passed to launch command is incorrect you will see a "no association" message appear in the field.

Simulators do not have the ability to place a phone call so you will get result string as message described above. You will need to build the app and deploy it to your phone to test.

The screenshots above are taken in the simulator (left) and from my iPhone (right)