Never make promises to your kid!

Natalya just finished her final exam last week. The exams started on 2 - 4 November 2009. Before that period, my hubby and I keep on monitoring her to make revision as we would like her to improve on her studies as on her mid term exam she didn't perform well. Actually we were just encourage her to do better than before as mid term exams she managed to get number 7 out of 45. And we were proud of it!
While on the way driving off sometimes last week Natalya noticed of Emart Fun Fair was set up, so she insisted to go there. I informed her only after she finished her exam and that only we can go there and enjoyed ourselves. But when she finished her exams this week Natalya keep on asking about that fun fair, so we promised her to go there during weekend and when weekend comes, my family had some function to deal with and again we were unable to make it again. So my family and my sister promised to bring her there on 9 November 2009 which means yesterday. But on that particular day, again I gave her some unspecific reasons and wouldn't be able to go to fun fair. Natalya cried out loud yesterday and it makes me feel out of temper. For the purpose to go the fun fair, I instructed her to do some light house-chores in regards to bring her there..she managed to make it done with all heart, and it makes me feel sad. I told her not to use her daddy's money or her auntie's money if she went to fun fair and I remind her to bring her own money..again she listen to my instruction and counting the money she had and brought RM5.00 (all coins) and I gave her RM3.00 for entrance fee.
According to her daddy, she really enjoyed that moment though it tooks only 1 hour for her, daddy and her auntie enjoyed at fun fair. Last nite I feel uneasy thought that I might broke up my promises to my daughter. Though I thought she is still a small kid but she always remember with all the promises given to her..In regards of that she is willing to do whatever instructed/given so that the promises will be fullfilled. Last but not least, never make promises to your kid when you think you cannot make it!