Parameters Validation

[MarcoFrancisco]

If one of the following parameter is blank, user should be forced to input values. No $exchangeOnPremEWS makes the script fail or have multiple errors.

Parameters (Function ShowParameters, line 184):

    Write-Host  -ForegroundColor White " Log File Path:"
    Write-Host -foregroundcolor Green "  $PSScriptRoot\$Logfile"
    Write-Host  -ForegroundColor White " Office 365 Domain:"
    Write-Host -foregroundcolor Green "  $exchangeOnlineDomain"
    Write-Host  -ForegroundColor White " AD root Domain"
    Write-Host -foregroundcolor Green "  $exchangeOnPremLocalDomain"
    Write-Host -foregroundcolor White " Exchange On Premises Domain:  "
    Write-Host -foregroundcolor Green "  $exchangeOnPremDomain"
    Write-Host -ForegroundColor White " Exchange On Premises External EWS url:"
    Write-Host -foregroundcolor Green "  $exchangeOnPremEWS"
    Write-Host -ForegroundColor White " On Premises Hybrid Mailbox:"
    Write-Host -foregroundcolor Green "  $useronprem"
    Write-Host -ForegroundColor White " Exchange Online Mailbox:"
    Write-Host -foregroundcolor Green "  $userOnline"