// #######################################################################
// ## common used javascript functions                                  ##
// #######################################################################


function nextField(elem, len, strNext) {
	if(elem.value.length >= len) {
		document.form.elements[strNext].focus();
	}
}

function colorTableRows (tableId, firstColor, secondColor) {
   var table;
   if (document.all)
     table = document.all[tableId];
   else if (document.getElementById)
     table = document.getElementById(tableId);
   
   if (!table)
     return;
     
   for (var r = 0; r < table.rows.length; r++)
   {
     table.rows[r].style.backgroundColor = (r % 2 == 0 ? firstColor : secondColor);
   }
}

function URLEncode(plaintext)
{
  if (! plaintext) return "";

	// The Javascript escape and unescape functions do not correspond
	// with what browsers actually do...
	var SAFECHARS = "0123456789" +					// Numeric
					"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +	// Alphabetic
					"abcdefghijklmnopqrstuvwxyz" +
					"-_.!~*'()";					// RFC2396 Mark characters
	var HEX = "0123456789ABCDEF";

	var encoded = "";
	for (var i = 0; i < plaintext.length; i++ ) {
		var ch = plaintext.charAt(i);
	    if (ch == " ") {
		    encoded += "+";				// x-www-urlencoded, rather than %20
		} else if (SAFECHARS.indexOf(ch) != -1) {
		    encoded += ch;
		} else {
		    var charCode = ch.charCodeAt(0);
			if (charCode > 255) {
			    alert( "Unicode Character '" 
                        + ch 
                        + "' cannot be encoded using standard URL encoding.\n" +
				          "(URL encoding only supports 8-bit characters.)\n" +
						  "A space (+) will be substituted." );
				encoded += "+";
			} else {
				encoded += "%";
				encoded += HEX.charAt((charCode >> 4) & 0xF);
				encoded += HEX.charAt(charCode & 0xF);
			}
		}
	} // for

	return encoded;
};

function URLDecode(encoded)
{
   // Replace + with ' '
   // Replace %xx with equivalent character
   // Put [ERROR] in output if %xx is invalid.
   var HEXCHARS = "0123456789ABCDEFabcdef"; 
   var plaintext = "";
   var i = 0;
   while (i < encoded.length) {
       var ch = encoded.charAt(i);
	   if (ch == "+") {
	       plaintext += " ";
		   i++;
	   } else if (ch == "%") {
			if (i < (encoded.length-2) 
					&& HEXCHARS.indexOf(encoded.charAt(i+1)) != -1 
					&& HEXCHARS.indexOf(encoded.charAt(i+2)) != -1 ) {
				plaintext += unescape( encoded.substr(i,3) );
				i += 3;
			} else {
				alert( 'Bad escape combination near ...' + encoded.substr(i) );
				plaintext += "%[ERROR]";
				i++;
			}
		} else {
		   plaintext += ch;
		   i++;
		}
	} // while
   return plaintext;
};


function change_to(element) {
	element.style.border ='1 dotted blue';
	element.style.color ='blue';
	element.style.backgroundColor ='#CCCCCC';
}

function change_back(element) {
	element.style.border ='1 solid red';
	element.style.color ='red';
	element.style.backgroundColor ='#FFFFFF';
}

function getPostForm(name){
  var post="";
  var el = document.forms[name].elements;
  for(i=0; i < el.length; i++)  {
    if (post){ post=post+"&" };
    if (el[i].type.toLowerCase()=="checkbox"){
      if (el[i].checked){
        post=post+URLEncode(el[i].name)+"=checked";
      }else{
        post=post+URLEncode(el[i].name)+"=";
      }
    }else if (el[i].name){
      if (post){ post=post+"&" };
      post=post+URLEncode(el[i].name)+"="+URLEncode(el[i].value);
    }
  }
  return post;
}