This might seem a stupid question, but I'm really new to japanese, and this question/problem seems to be following me!!
I've just learned the entire hiragana, and in my world, wa is written わ. But apparently it's not always so - in different phrases written here on this site and in my dictionary and other palces on the internet for instance, I sometimes see wa written as は. How come?

Domo arigato in advance!

//Maria