LCD and keypad programming

Hello everyone, i'm kinda new in arduino.. I really need a guidance for my programming.. I want to use arduino for my project..the one i use is arduino mega.. I want to use keypad and LCD for input and ouput.. my project is about heating process.. The keypad is used for input desire value.. the problem is..how to display it on LCD with only 3 digit maximum.. and the maximum value is 100, more than that will give error message.. can some help me..Thanks in advance..

You could use Celsius - 100 degrees is the boiling point of water, so you should never go anywhere near 99.

Since you have three digits, can you display decimals? If so, then scale the values - divide by 10 and display that, so 100 would appear as 10 - well within range.

tarnatos: the problem is..how to display it on LCD with only 3 digit maximum.. and the maximum value is 100, more than that will give error message.. can some help me..Thanks in advance..

What is "it"? Is it a number? Is it float? What do you mean by 3 digit? Like 3.14? Or 123? Or 12.3? What do you mean more than 100 gets error message, from where?

Do you have any code?

sorry for my bad english.. u can take a look at this first: http://www.youtube.com/watch?v=JiLDdG8-x4A&feature=related i want to make something similar like that.. when we press keypad number.. the lcd will display what we press.. i'm kinda new with programming.. i try once and the result show randomly.. sometime the number show up in the middle first.. sometime the number show up in the right corner first..

You can start by telling us what hardware you use, what display and what kind of keypad. Provide links to where you bought them. Then we can look at your code and see if your code is doing what you want.