Javascript DOM Form Radio Button
<!DOCTYPE html> <html lang="en"> <body> <form action="" name="form1"> <p> Tick all of the components you want included on your computer </p> <p> <label for="chkDVD">DVD-ROM</label> <input type="checkbox" id="chkDVD" name="chkDVD" value="DVD-ROM" /> </p> <p> <label for="chkBluRay">Blu-ray</label> <input type="checkbox" id="chkBluRay" name="chkBluRay" value="Blu-ray" /> </p> <p> Select the processor speed you require </p> <p> <input type="radio" name="radCpuSpeed" checked="checked" value="3.2 ghz" /> <label>3.2 GHz</label> <input type="radio" name="radCpuSpeed" value="3.7 ghz" /> <label>3.7 GHz</label> <input type="radio" name="radCpuSpeed" value="4.0 ghz" /> <label>4.0 GHz</label> </p> <input type="button" value="Check form" name="btnCheck" /> //from ww w .j a v a2 s .c om <p id="demo"></p> </form> <script> let myForm = document.form1; function getSelectedSpeedValue() { let radios = myForm.radCpuSpeed; for (let index = 0; index < radios.length; index++) { if (radios[index].checked) { return radios[index].value; } } return ""; } function findIndexOfSpeed(radio) { let radios = myForm.radCpuSpeed; for (let index = 0; index < radios.length; index++) { if (radios[index] == radio) { return index; } } return -1; } function radCpuSpeedClick(e) { let radIndex = findIndexOfSpeed(e.target); if (radIndex == 1) { e.preventDefault(); document.getElementById("demo").innerHTML = "Sorry that processor speed is currently unavailable"; // to fix an issue with IE myForm.radCpuSpeed[0].checked = true; } } function btnCheckClick() { let numberOfControls = myForm.length; let compSpec = "Your chosen processor speed is "; compSpec = compSpec + getSelectedSpeedValue(); compSpec = compSpec + "\nWith the following additional components:\n"; for (let index = 0; index < numberOfControls; index++) { let element = myForm[index]; if (element.type == "checkbox") { if (element.checked) { compSpec = compSpec + element.value + "\n"; } } } document.getElementById("demo").innerHTML = compSpec; } for (let index = 0; index < myForm.radCpuSpeed.length; index++) { myForm.radCpuSpeed[index].addEventListener("click", radCpuSpeedClick); } myForm.btnCheck.addEventListener("click", btnCheckClick); </script> </body> </html>