robertpateii/checkboxesarechecked.js

## checkboxesarechecked.js
// Used to check through an array of checkboxes or radio buttons with the same name attribute.
// max is an integer and is optional. it defaults to 1 if left empty.
function checkBoxesAreChecked(checkboxarray, max) {
    var arraymax = max || 1;
    var checkedcount = 0;
    for (var i=0; i < checkboxarray.length; i++) {
        if (checkboxarray[i].checked) {
            checkedcount++;
        }
    }
    if (checkedcount > 0 && checkedcount <= arraymax) {
        return true;
    } else {
        return false;
    }
}


// If you don't have any validation framework or jQuery, here's some samples to get you through

var validateForm = function (e) {
    var e = e || window.event;
    if (checkBoxesAreChecked(document.getElementsByName("NameOfCheckboxes")) === true) {
        return true;
    } else {
        e.preventDefault ? e.preventDefault() : e.returnValue = false;
        alert("Please select at least 1 option to proceed.");
        return false;
    }

};

var attachToForm = function () {
  var formElement = document.getElementById("form");
  if (formElement.addEventListener) {
    formElement.addEventListener("submit", validateForm, false);
  } else {
    formElement.attachEvent('onsubmit', validateForm);
  }
};

// If running in <head> here's a basic onload listener.
// Otherwise if running at the bottom of <body> just call attachToForm()
if (window.addEventListener) {
 window.addEventListener("load", attachToForm, false);
} else {
 window.attachEvent("onload", attachToForm);
}
	// Used to check through an array of checkboxes or radio buttons with the same name attribute.
	// max is an integer and is optional. it defaults to 1 if left empty.
	function checkBoxesAreChecked(checkboxarray, max) {
	var arraymax = max \|\| 1;
	var checkedcount = 0;
	for (var i=0; i < checkboxarray.length; i++) {
	if (checkboxarray[i].checked) {
	checkedcount++;
	}
	}
	if (checkedcount > 0 && checkedcount <= arraymax) {
	return true;
	} else {
	return false;
	}
	}


	// If you don't have any validation framework or jQuery, here's some samples to get you through

	var validateForm = function (e) {
	var e = e \|\| window.event;
	if (checkBoxesAreChecked(document.getElementsByName("NameOfCheckboxes")) === true) {
	return true;
	} else {
	e.preventDefault ? e.preventDefault() : e.returnValue = false;
	alert("Please select at least 1 option to proceed.");
	return false;
	}

	};

	var attachToForm = function () {
	var formElement = document.getElementById("form");
	if (formElement.addEventListener) {
	formElement.addEventListener("submit", validateForm, false);
	} else {
	formElement.attachEvent('onsubmit', validateForm);
	}
	};

	// If running in <head> here's a basic onload listener.
	// Otherwise if running at the bottom of <body> just call attachToForm()
	if (window.addEventListener) {
	window.addEventListener("load", attachToForm, false);
	} else {
	window.attachEvent("onload", attachToForm);
	}