禁用提交按钮，直到完成所有字段

Question

I am trying to disable the submit button until all the fields are completed. I have written a code for this but it isn't working. The submit button is enabled all the time even if the values are not entered in the fields. Any help please? Below is the html code:

 $(document).ready(function () { validate(); $('#Quarter, #Year, #LineID').change(validate); }); function validate() { if ($('#Quarter').val()!="--Select Quarter--" && $('#Year').val()!="--Select Year--" && $('#LineID').val().length > 0 { $("input[type=submit]").prop("disabled", false); } else { $("input[type=submit]").prop("disabled", true); } } 

 <div class="row"> <div class="col-lg-8"> <div class="form-horizontal"> <div class="form-group"> <label class="control-label col-lg-4">Period:</label> <div class="col-lg-8"> @Html.DropDownList("Quarter", new SelectListItem[] { (new SelectListItem() { Text = "Q1", Value = "1" }), (new SelectListItem() { Text = "Q2", Value = "2" }), (new SelectListItem() { Text = "Q3", Value = "3" }), (new SelectListItem() { Text = "Q4", Value = "4" }) },"--Select Quarter--", new { @class = "form-control" }) <br /> @Html.DropDownList("Year", new SelectListItem[] { (new SelectListItem() { Text = "2016", Value = "2016" }), (new SelectListItem() { Text = "2017", Value = "2017" }) },"--Select Year--", new { @class = "form-control" }) </div> </div> </div> <div class="form-horizontal"> <div class="form-group"> <label class="control-label col-lg-4">Line ID:</label> <div class="col-lg-8"> @Html.TextBoxFor(model => model.floorConfig.LineID, new { onkeypress = "return isNumberKey(event)", @class = "form-control" }) </div> </div> </div> <div class="row"> <div class="col-lg-offset-4" style="padding: 10px 0px 0px 0px;"> <input type="submit" id="submit" value="Submit" class="btn btn-lg btn-success" /> <input type="button" id="btnCancel" value="Clear" class="btn btn-lg btn-success" /> </div> </div> </div> </div> 

Answer 1

Aren't you just missing the closing bracket from your IF statement? JS Fiddle

Answer 2

I need to add id for Quarter and Year. It works now!