function char2hex(c)
{
 c=c+'';
 var n=c.charCodeAt(0);
 var result=parseInt(n, 10).toString(16);
 if(result.length==1) result='0'+result;
 return result;
}

function hex2char(h)
{
 h=h+'';
 var n=parseInt(h,16);
 return String.fromCharCode(n);
}

function str2hex(str)
{
 var result='';
 for(var i=0; i < str.length; i+=1)
  result += char2hex(str.substring(i, i+1));
 return result;
}

function hex2str(hex)
{
 var result='';
 for(var i=0; i < hex.length; i+=2)
  result += hex2char(hex.substring(i, i+2));
 return result;
}