Why I am getting error at Internet Explorer 7.0 and 8.0?

Question

I use custom validation for my field

<div class="control-group">
  <label class="control-label" for="region">Region*</label>
  <div class="controls">
    <input type="text" class="input-xlarge" id="region" name="region" minlength="1" maxlength="50" autocomplete="off">
  </div>
</div>

var regionsList = ["value1", "value2", ..., "value 80"];

$.validator.addMethod("validRegion", function (value, element, param) {
  return this.optional(element) || (param.indexOf(value) != -1); // ERROR IS HERE
}, "Please start to type and choose correct value");

$("#myform").validate({
  rules: {
    "region": {
      required: true,
      validRegion: regionsList
    },
 ...

What can be wrong at this line (please look for the line with comment ERROR IS HERE)? The error is Object doesn't support this property or method.

Answer 1

Array.indexOf is only supported on IE 9+. Since you are already using jQuery, you can use $.inArray (it will use Array.indexOf if its supported).

$.validator.addMethod("validRegion", function (value, element, param) {
  return this.optional(element) || ($.inArray(value, param) != -1);
}, "Please start to type and choose correct value");