declaring variables in PHP???

Hi, I'm using PHP for a few weeks now, so you can imagine that I'm making a lot of typing errors... Often I make a typing error in one of the variable names ($helo instead of $hello or worse still $Hello instead of $hello). Since PHP does not care about declaring variables before using them, it is very easy to overlook such small typing error in a large PHP script. In the old days of ANSI C, there where things like LINT that would help you with these problems. Of course in ANSI C these things were easier, because of the fact that variables need to be declared before they could be used. My questions: 1. can you configure PHP in such away that variables need to be declared? 2. are there source code checking tools that could help me locate problems like described above? Thanks for your help René