Font does not exits on target device- iPhone issue?

I am getting the following Error:

2011-08-01 11:49:28.511 ClueMe[2192:207] *** Assertion failure in -[UILabel setFont:], /SourceCache/UIKit/UIKit-984.38/UILabel.m:445
2011-08-01 11:49:28.516 ClueMe[2192:207] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid parameter not satisfying: font != nil'<!>2011-08-01 11:49:28.522 ClueMe[2192:207] Stack: (
    861696817,
    860329709,
    861252493,
    846164395,
    834808043,
    166301,
    835250561,
    835249847,
    834989695,
    834983899,
    834971003,
    805539851,
    805539363,
    805538115,
    805537449,
    805560369,
    861158231,
    861448761,
    861447005,
    861059891,
    861060063,
    834770799,
    834765939,
    9009,
    8952
)
terminate called after throwing an instance of 'NSException'

Here the code line where it break on iPhone iOS 3.1.2

cell.detailTextLabel.font = [UIFontfontWithName: @"Monaco"size: 10];

Answer

Mostly that fond Monaco does not existing on the iPhone. Either check for the font existing on the target system before using the Font or replace it with a existing font.

cell.detailTextLabel.font = [UIFontfontWithName: @"Georgia"size: 10];