Invoke-Translit (Bad version)

Function Invoke-Translit {
    Param (
        [Parameter(Mandatory=$true,Position=0)]
        [string]$RussianFullName
    )
    $Local:NewFullName = $RussianFullName;

    $Local:TranslitTable = @{
        'а' =  @{'Translit' = 'a';};
        'б' =  @{'Translit' = 'b';};
        'в' =  @{'Translit' = 'v';};
        'г' =  @{'Translit' = 'g';};
        'д' =  @{'Translit' = 'd';};
        'е' =  @{'Translit' = 'e';};
        'ё' =  @{'Translit' = 'e';};
        'ж' =  @{'Translit' = 'zh';};
        'з' =  @{'Translit' = 'z';};
        'и' =  @{'Translit' = 'i';};
        'й' =  @{'Translit' = 'y';};
        'к' =  @{'Translit' = 'k';};
        'л' =  @{'Translit' = 'l';};
        'м' =  @{'Translit' = 'm';};
        'н' =  @{'Translit' = 'n';};
        'о' =  @{'Translit' = 'o';};
        'п' =  @{'Translit' = 'p';};
        'р' =  @{'Translit' = 'r';};
        'с' =  @{'Translit' = 's';};
        'т' =  @{'Translit' = 't';};
        'у' =  @{'Translit' = 'u';};
        'ф' =  @{'Translit' = 'f';};
        'х' =  @{'Translit' = 'kh';};
        'ц' =  @{'Translit' = 'ts';};
        'ч' =  @{'Translit' = 'ch';};
        'ш' =  @{'Translit' = 'sh';};
        'щ' =  @{'Translit' = 'sch';};
        'ъ' =  @{'Translit' = '';};
        'ы' =  @{'Translit' = 'y';};
        'ь' =  @{'Translit' = '';};
        'э' =  @{'Translit' = 'e';};
        'ю' =  @{'Translit' = 'yu';};
        'я' =  @{'Translit' = 'ya';};
    }

    $local:newCharArray = @();
    $local:charArray = $RussianFullName.ToCharArray()
    foreach ($local:char in $local:charArray) {
        $local:isUpperCase =  [System.Char]::IsUpper($local:char)
        $local:original_char_lowercase = [System.Char]::ToLower($local:char)
        $local:new_char_lowercase_as_string = $local:original_char_lowercase.toString()
        $local:original_char_lowercase_as_string = $local:original_char_lowercase.toString()
        if ($Local:TranslitTable.ContainsKey($local:original_char_lowercase_as_string)) {
            $local:new_char_lowercase_as_string = $Local:TranslitTable[$local:original_char_lowercase_as_string].Translit
        }

        $local:new_chars = $local:new_char_lowercase_as_string.toCharArray()
        if ($local:isUpperCase) {
            $local:new_chars[0] = $local:new_chars[0].toString().toUpper().toCharArray()[0]
        }
        $local:newCharArray += @($local:new_chars);
    }



    $local:ret_data = [String]::Join('',$local:newCharArray)
    $local:non_ascii = @( $local:ret_data.ToCharArray() | Where-Object {
        (
            (
                ( [System.Int32]$_ ) -gt 126
            ) -or  (
                ( ( [System.Int32]$_ ) -lt 32 )
            ) ) } )
    if ( $local:non_ascii.Count -gt 0  )  {
        throw "Error! Data contains non-ASCII symbols! : [$($local:non_ascii -join ',')]"
        return $null
    }
    return $local:ret_data