How to control progress bar from two different tasks - nsis

Question

I have a custom page, and and added a progress bar. Now I have two functions to control that progress bar. One function is to stop few services and other is to back up some files from install location.
Function myCustomPage
Var /GLOBAL progressBar
Var /GLOBAL label
!insertmacro MUI_HEADER_TEXT "Setup is preaparing to install updates" "Please wait"
nsDialogs::Create 1018
${NSD_CreateLabel} 10 15 80% 10% ""
Pop $label
${NSD_CreateProgressBar} 10 30 80% 8% ""
Pop $progressBar
${NSD_CreateTimer} BackUp_Files.Callback 10
${NSD_CreateTimer} Stop_Services.Callback 10
nsDialogs::Show
FunctionEnd
Stop_Services call back function
Function Stop_Services.Callback
${NSD_SetText} $label "Stopping services"
${NSD_KillTimer} Stop_Services.Callback
SendMessage $progressBar ${PBM_SETRANGE32} 0 100
SendMessage $progressBar ${PBM_SETPOS} 25 0
Sleep 100
SendMessage $progressBar ${PBM_SETPOS} 25 0
Sleep 100
SendMessage $progressBar ${PBM_SETPOS} 50 0
Sleep 100
SendMessage $progressBar ${PBM_SETPOS} 75 0
Sleep 100
SendMessage $progressBar ${PBM_SETPOS} 100 0
FuncionEnd
Same kind of structure for Backup_files.callback has.
Result:
When I look at the label its kind of switching between "stopping services" and "backing up files".
Can any one tell me how to handle this. I want to stop the services first then I want to copy the backup files. Progress bar needs to be set to 0 after stopping the services and start again for backing up files. I need to do it on single custom page.

Answer 1

Just use one timer and at the end of the first task call the second task function directly...