Function ConvertCurrencies
{
    param (
        [Parameter(Mandatory=$true)][Double]$amount,
        [switch]$EURUSD,
        [switch]$USDEUR,
        $rateEURUSD = 1.12,
        $rateUSDEUR = 0.9
    )
    if ($EURUSD -eq $true) {
        $conv = $amount * $rateEURUSD
        Write-Host "$amount euro(s) = $conv dollar(s)"
    } elseif ($USDEUR -eq $true) {
        $conv = $amount * $rateUSDEUR
        Write-Host "$amount dollar(s) = $conv euro(s)"
    } else {
        Write-Host "You need to specify the way of exchanging by using -EURUSD or -USDEUR"
    }
}