/**
* param geo_x1、geo_y1、geo_x2、geo_y2
* return distance (meter)
*/
function get_distance(x1,y1,x2,y2){
	var p1 = 101192.44592099363;
	var p2 = 111194.87428470024;
	var dx = (x1>x2)?(x1-x2)*p1:(x2-x1)*p1;
 	var dy = (y1>y2)?(y1-y2)*p2:(y2-y1)*p2;
 	return Math.floor(Math.sqrt(dx*dx+dy*dy));
}
	
function judge_bounds(x,y){
	return (x>=118.049765603027)&&(x<=118.197998011716)&&(y>=24.4208474579424)&&(y<=24.5557457623516);
}

function prt_distance(p_centerX, p_centerY, map_x, map_y)
{
	var distance = -1;
	distance = get_distance(p_centerX, p_centerY, map_x, map_y);
	
	if(distance > 100)
	{
	  var a,b;
	  a = (distance/1000).toString();
	  b = a.indexOf('.');
	  distance = a.substring(0, b+2);
	  document.write("大约距离我" + distance + "公里&nbsp;&nbsp;");
	}
	else if(distance < 100 && distance > 0)
	{
	  document.write("距离我少于0.1公里&nbsp;&nbsp;");
	}
}