==== MFSH_LOCK - Lock a segment ====

**Purpose**

Lock a segment in place in physical memory.   

**Calling Sequence**

<code c>
int far pascal MFSH_LOCK(usSel, pulHandle)

unsigned short usSel;
unsigned long far * pulHandle;
</code>

**Where**

//usSel// is the selector of the segment to be locked.   

//pulHandle// is a pointer to a double word which is filled in by the helper with the lock handle. 

**Returns**

If no error is detected, a zero error code is returned. If an error is detected, one of the following error codes is returned:   

  * ERROR_PROTECTION_VIOLATION -- the supplied address or selector is invalid. 

**Remarks**

This helper is for use by a mini-FSD with an imbedded device driver. It is the same as the standard device driver LOCK helper with the following assumptions: The lock is defined to be short term and will block until the segment is loaded.