Checks if the specified directory exists
| Number | Type | Compulsory | Default | Description | 
| 1 | string | Yes | Directory name | 
Return type: real
Function returns a real scalar with one of three values:
| Index | Description | 
| 0 | Directory does not exist | 
| 1 | Directory exists with write privilege | 
| 2 | Directory exists but with no write privilege | 
| ▲Function Summary▲ | ||
| ◄ ExistCommand | ExistFile ▶ | |