Help with For Loop using Double

 
for(p=LowestBuy();;p-=0.0001)
This gives me 'unbalanced parenthesis' errors when I try to compile it.  Can you do for loops based on a double data type in MT4?  If so, what am I doing wrong?
 

doubles for loop counter is OK.

 
Thanks phy.  So what's wrong?  Can't use a custom function in a for loop?  Incrementing wrong?
 

Who can tell from one line of code. Not me.

 
OK, so you're saying that there is nothing at all wrong with the one line I have here?
 
Can anybody show me a loop using doubles?
 

for( double i = 1; i < 2; i += 0.01){

Print(i);

}