add avg function

calc.html

@@ -4,7 +4,7 @@
 
 <script language=javascript type="text/javascript">
 
-var plus,minus,divide,multiply,max,pow,min
+var plus,minus,divide,multiply,max,pow,min,avg
 
 function initialize(){
  plus=document.calc.operator.options[0]
@@ -14,6 +14,7 @@
  max=document.calc.operator.options[4]
  pow=document.calc.operator.options[5]
  min=document.calc.operator.options[6]
+ avg=document.calc.operator.options[7]
 }
 
 function calculate(){
@@ -33,6 +34,8 @@
 		document.calc.answer.value = Math.pow(a,b)
 	if (min.selected)
 		document.calc.answer.value = Math.min(a,b)
+	if (avg.selected)
+		document.calc.answer.value = (a + b) / 2
 }
 
 </script>
@@ -56,6 +59,7 @@ <h2>Calc</h2>
 <option value=max>max
 <option value=pow>**
 <option value=min>min
+<option value=avg>avg
 </select>
 
 <input type=text name=val2 size=10>