glIsList - determine if a name corresponds to	a display-list

glIsList
	glIsList(list) -> boolean

GLboolean glIsList( GLuint list )

list	Specifies a potential display-list name.

glIsList returns GL_TRUE if list is the name of a display
list and returns GL_FALSE otherwise.

GL_INVALID_OPERATION is generated if glIsList	is executed
between the execution	of glBegin and the corresponding
execution of glEnd.

glCallList, glCallLists, glDeleteLists, glGenLists,
glNewList