function langswap(){
      var src = document.getElementById('src').value;
      document.getElementById('src').value = document.getElementById('dst').value;
      document.getElementById('dst').value = src;
      
      return true;
    }

function conta(){
     var lenMax=250
     var strlength=document.mform.source.value.length
     total = eval("1500")
     char = eval(document.mform.source.value.length)
     left = eval(total - char)
     if (left <= "-1")
     {
     var dif = eval(char - 1500)
     var value = document.mform.source.value.substr(0,char-dif);
     document.mform.source.value = value;
     var left = "0"
     }
     document.mform.zbyva.value=left
 }
 
function translate() {
        document.getElementById('results_body').innerHTML="";
        var text= document.getElementById('source').value;
        window.mycallback = function(response) {
        document.getElementById('results_body').innerHTML=response;
        }
        var languageFrom = document.getElementById("src").value;
        var languageTo = document.getElementById("dst").value;
        var s = document.createElement("script");
        s.src = "http://api.microsofttranslator.com/V2/Ajax.svc/Translate?oncomplete=mycallback&appId=8B841CA7C1A03443682C52AD07B7775A7BD5B3AA&from=" + languageFrom + "&to=" + languageTo + "&text=" + text;
        document.getElementsByTagName("head")[0].appendChild(s);
    }