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<html xmlns="http://www.w3.org/1999/xhtml"><head><title></title><script type="text/javascript"> window.onload=function() { lengthObj = document.getElementById('txtLength'); girthObj = document.getElementById('txtGirth'); weightObj = document.getElementById('tdWeight'); document.getElementById('btnReset').onclick = resetInputs; document.getElementById('btnCalc').onclick = calcWeight; } function resetInputs() { lengthObj.value = ''; girthObj.value = ''; weightObj.innerHTML = ''; } function calcWeight() { var length = new Number(lengthObj.value); var girth = new Number(girthObj.value); weightObj.innerHTML = ''; if(isNaN(length) || isNaN(girth)) { alert('Invalid length or girth'); return; } weightObj.innerHTML = length*Math.pow(girth,2)/800; } </script></head><body> <table> <tr> <td><label for="txtLength">Length (inches)</label></td> <td><input type="text" id="txtLength" /></td> </tr> <tr> <td><label for="txtGirth">Girth (inches)</label></td> <td><input type="text" id="txtGirth" /></td> </tr> <tr> <td>Weight</td> <td id="tdWeight"></td> </tr> <tr> <td></td> <td><button id="btnReset">Reset</button><button id="btnCalc">Calculate</button></td> </tr> </table> </body></html>