Hey I'm really new to javascript and i just don't understand why it won't print on my document a number increasing every time i click on my button
<script type="text/javascript">
var x = 0;
function clicker(
y = x+1
)
document.write(y)
return clicker();
</script>
<form name="click">
<input type="button" name="derp" onclick="clicker()">
</form>