text: function addChar(C){
  	document.form.textview.value = document.form.textview.value+C
  }
  
  function compute(){
  	var exp = document.form.textview.value;
  	if(exp){
  	  document.form.textview.value = stringMath(exp)
  	}
  }	
  
  function removeAllChar(){        
  	document.form.textview.value = "";
  }
  
  function removeOneChar(){
  	var exp = document.form.textview.value;
  	if(exp){
  	  document.form.textview.value = exp.substring(0, exp.length-1);
  	}
  }
  
  function dispChar(e){
  	if(e.keyCode==13){
  		compute();
  		return false;
  	}	
  	
  }
  
  function convert(){
  	
  	var liste, from_unit, to_unit, subject;
  	
  	liste = document.getElementById("from");
  	from_unit = liste.options[liste.selectedIndex].text;
  
  	liste = document.getElementById("to");
  	to_unit = liste.options[liste.selectedIndex].text;
  	
  	liste = document.getElementById("subject");
  	subject = liste.options[liste.selectedIndex].text;
  	
  	document.form.textview.value = conversionObject.functions.converter(subject, from_unit, to_unit, document.form.textview.value);
  
  }
  
  function setSubject(){
  	
  	var liste, subject;
  	
  	liste = document.getElementById("subject");
  	subject = liste.options[liste.selectedIndex].text;
  	
  	setSelectChoices(subject)
  	
  }
  
  function setSelectChoices(subject){
  	
  	var liste_from, liste_to
  	
  	liste_from = document.getElementById("from");
  	liste_to = document.getElementById("to");
  	
  	liste_from.options.length = 0;
  	liste_to.options.length = 0;
  	
  	for (var key in conversionObject.master[subject]){		
  		liste_from.options[liste_from.length] = new Option(key,key);
  		liste_to.options[liste_to.length] = new Option(key,key);		
  	}
  	
  }
  