$A = x(point) - x(line point 1);
	$B = y(point) - y(line point 1);
	$C = x(line point 2) - x(line point 1);
	$D = y(line point 2) - y(line point 1);
	 
	$dot = (($A * $C) + ($B * $D));
	$len_sq = ((C * C) + (D * D));
	$param = (dot / len_sq);
	 
	if($param < 0)
	{
	    $xx = x(line point 1);
	    $yy = y(line point 2);
	}
	else if($param > 1)
	{
	    $xx = $x(line point 2);
	    $yy = $y(line point 2);
	}
	else
	{
	    $xx = x(line point 1) + $param * $C;
	    $yy = y(line point 1) + $param * $D;
	}
	 
$dist = sqrt((($x(point) - $xx) * ($x(point) - $xx)) + (($y(point) - $yy) * ($y(point) - $yy)) + (($z(point) - $zz) * ($z(point) - $zz)));