Small program :<BR>
<TEXTAREA   Name=TextArea1   Rows=18   Cols=79   Wrap=Off   >
//----- Variables
var  x = 3 ;
var  y = 4 ;

//----- Main expression
x * x  +  y * y
</TEXTAREA>


<BLOCKQUOTE>
   <INPUT   Type=BUTTON   Value="Evaluate"
      OnClick="EditResult.value=eval(TextArea1.value);"   > &nbsp; &nbsp;

   Result : 
   <INPUT   Type=TEXT   Name=EditResult   Size=25   Value=""   >
</BLOCKQUOTE>