Increase number of instances in a Azure scaleset

CapacityVmss.ps1

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# Author: Alexandre Verkinderen
# Company: cubesys
# date: 05/09/2017
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#Login-AzureRmAccount

#region variables
#select resource Group
$rgName = ( Get-AzureRmResourceGroup | Out-GridView -Title "Select an Azure Resource Group ...and press Enter" -PassThru).ResourceGroupName

#Select Virtual Machine ScaleSet
$vmss = ( Get-AzureRmVmss -ResourceGroupName $rgName | Out-GridView -Title "Select a scale set ...and press Enter" -PassThru)

$capacity = Read-Host -Prompt 'Provide new capacity'

$caption = "Confirm"
$message = "Are you sure you want to increase the number of instances for scale set " + $vmss.Name + " from resource group " + $rgName
$yes = new-Object System.Management.Automation.Host.ChoiceDescription "&Yes","help"
$no = new-Object System.Management.Automation.Host.ChoiceDescription "&No","help"
$choices = [System.Management.Automation.Host.ChoiceDescription[]]($yes,$no)
#endregion


$answer = $host.ui.PromptForChoice($caption,$message,$choices,0)

switch ($answer){
    0 {

$vmss.sku.capacity = $capacity
Update-AzureRmVmss -ResourceGroupName $rgName -Name $vmss.Name -VirtualMachineScaleSet $vmss 

}
    1 {"You entered no"; break}
}