extern function calc()
{
var val1 = Lang.parseFloat(WMLBrowser.getVar("vala"));
var val2 = Lang.parseFloat(WMLBrowser.getVar("valb"));
var oper = WMLBrowser.getVar("oper");
var result;
if (oper == "0") result = val1 + val2;
if (oper == "1") result = val1 - val2;
if (oper == "2") result = val1 * val2;
if (oper == "3") result = val1 / val2;
WMLBrowser.setVar("result", result);
WMLBrowser.go("#result");
}