var MULTIPLIER= 1e+10;
    
    function updatevnt(f) {
       with (f) {
          dest.value = Math.round(MULTIPLIER*source.value*sourceu.value/destu.value)/MULTIPLIER;
       }
    }

    function updatetemp(f) {
       var MULTIPLIER= 1e+10;
       var C,X;
       
       with (f) {
          X = 1*source.value;

          if (sourceu.value == "C")
	     C = X;
          if (sourceu.value == "F")
	     C = (X - 32)/1.8;
          if (sourceu.value == "R")
	     C = X/1.8 - 273.16;
          if (sourceu.value == "Re")
	     C = X/0.8;
          if (sourceu.value == "K")
	     C = X - 273.16;

          if (destu.value == "C")
	     X = C;
          if (destu.value == "F")
	     X = 1.8*C + 32;
          if (destu.value == "R")
	     X = (C + 273.16)*1.8;
          if (destu.value == "Re")
	     X = C*0.8;
          if (destu.value == "K")
	     X = C + 273.16;

	  dest.value = Math.round(MULTIPLIER*X)/MULTIPLIER;
       }
    }