语法：

buffer_exists(buffer)

返回： 布尔值

描述

This function can be used to check a variable to see if it holds a valid buffer ID value or not. If it does the function will return true otherwise it will return false.

例如：

if buffer_exists(buff)
   {
   buffer_delete(buff);
   }

The above code checks to see if the variable "buff" holds a buffer ID and if it does, the buffer is deleted.