function something()
{
//some instructions
if(needtoquit)goto somethingend;
//more instructions
somethingend:
wait(1);
}

var functionIsRunning = 0;	// A global variable

function theFunction()
{
	// Set the variable to non-zero
	functionIsRunning = 1;
	
	// Run the function as long as functionIsRunning is non-zero
	while(functionIsRunning != 0)
	{
		... // Code
	}
}

function firstone()
{
    while(1)
    {
       if(xxx==0)
       {
           nextfunction();
           return;
       }
       wait(1);
    }
}

function breaking()
{
    while(1)
    {
       if(x == 0)
       {
           do_this();
           break; // Stops the while loop and continues after it
       }
       wait(1);
    }
    // Here could be more code
}