Wait loop program

I want to write a program where, I have a signal "B", when it goes LOW, the program waits. and when it is HIGH the program continues..
Can u help me guys...

That sounds like a while loop to me.

while (digitaRead(someInputPin) == LOW)
  //do nothing
//now do something

However, I am suspicious of your description of the requirement since you called the input signal "B". Where is this signal coming from ?

you should post some code......

while(check_signal_b() == false){
// wait if function returns false or low

write a function to check the signal check_signal_b() and return a boolean value

Thank u guys