function encodeURL(str){
	var s0, i, s, u;
	s0 = "";				// encoded str
	for (i = 0; i < str.length; i++){   // scan the source
		s = str.charAt(i);
		u = str.charCodeAt(i);		  // get unicode of the char
		if (s == " "){s0 += "+";}	   // SP should be converted to "+"
		else {
			if ( u == 0x2a || u == 0x2d || u == 0x2e || u == 0x5f || ((u >= 0x30) && (u <= 0x39)) || ((u >= 0x41) && (u <= 0x5a)) || ((u >= 0x61) && (u <= 0x7a))){	   // check for escape
				s0 = s0 + s;			// don't escape
			}
			else {				  // escape
				if ((u >= 0x0) && (u <= 0x7f)){	 // single byte format
					s = "0"+u.toString(16);
					s0 += "%"+ s.substr(s.length-2);
				}
				else if (u > 0x1fffff){	 // quaternary byte format (extended)
					s0 += "%" + (oxf0 + ((u & 0x1c0000) >> 18)).toString(16);
					s0 += "%" + (0x80 + ((u & 0x3f000) >> 12)).toString(16);
					s0 += "%" + (0x80 + ((u & 0xfc0) >> 6)).toString(16);
					s0 += "%" + (0x80 + (u & 0x3f)).toString(16);
				}
				else if (u > 0x7ff){		// triple byte format
					s0 += "%" + (0xe0 + ((u & 0xf000) >> 12)).toString(16);
					s0 += "%" + (0x80 + ((u & 0xfc0) >> 6)).toString(16);
					s0 += "%" + (0x80 + (u & 0x3f)).toString(16);
				}
				else {					  // double byte format
					s0 += "%" + (0xc0 + ((u & 0x7c0) >> 6)).toString(16);
					s0 += "%" + (0x80 + (u & 0x3f)).toString(16);
				}
			}
		}
	}
	return s0;
}