如果复选框已选中且文本框为空白

Question

I have a checkbox, on click of which the textbox gets enabled. I want to make validation that If checkbox is checked and the user doesn't put any data. It should not allow the user to submit the form. Please see the javascript code for your reference

Javascript :

<script type="text/javascript">
$(document).ready(function () {
    $('#chkCropLoan').change(function () {
        $("#txtAmount").prop("disabled", !$(this).is(':checked'));
        if (!$(this).is(':checked')) {
            $("#txtAmount").val("");
        }
    });
    $('#chkInvestmentLoan').change(function () {
        $("#txtInvestmentLoan").prop("disabled", !$(this).is(':checked'));
        if (!$(this).is(':checked')) {
            $("#txtInvestmentLoan").val("");
        }
    });
    $('#chkWarehouseReceipt').change(function () {
        $("#txtWarehouseReceipt").prop("disabled", !$(this).is(':checked'));
        if (!$(this).is(':checked')) {
            $("#txtWarehouseReceipt").val("");
        }
    });
    $('#chkFarmerProd').change(function () {
        $("#txtFarmerProd").prop("disabled", !$(this).is(':checked'));
        if (!$(this).is(':checked')) {
            $("#txtFarmerProd").val("");
        }
    });
});
</script>

HTML code of textbox :

<table>
    <tr>
        <td>Crop Loan</td>
        <td>
            <asp:CheckBox ID="chkCropLoan" runat="server" CssClass="check" onclick="javascript:enableTextBox();" />
            <asp:TextBox ID="txtAmount" runat="server" class="txtfld-popup1" MaxLength="5" Width="100" onkeypress="if(event.keyCode<48 || event.keyCode>57)event.returnValue=false;" Enabled="false"></asp:TextBox>
            <cc1:TextBoxWatermarkExtender ID="txtAmount_TextBoxWatermarkExtender" runat="server" TargetControlID="txtAmount" WatermarkText="Amount"></cc1:TextBoxWatermarkExtender>
            <asp:RegularExpressionValidator ID="rgfldvalidator" ControlToValidate="txtAmount"
                runat="server" ErrorMessage="Please enter the numbers only" ValidationExpression="^[0-9]*\.?[0-9]+$"></asp:RegularExpressionValidator>
        </td>
    </tr>

    <tr>
        <td>Investment Loan</td>
        <td>

            <asp:CheckBox ID="chkInvestmentLoan" runat="server" CssClass="check" OnChange="javascript:enableTextBox();" />
            <asp:TextBox ID="txtInvestmentLoan" runat="server" class="txtfld-popup1" MaxLength="5" width="100" onkeypress="if(event.keyCode<48 || event.keyCode>57)event.returnValue=false;" Enabled="false"></asp:TextBox>
            <cc1:TextBoxWatermarkExtender ID="txtInvestmentLoan_TextBoxWatermarkExtender" runat="server" TargetControlID="txtInvestmentLoan" WatermarkText="Amount"></cc1:TextBoxWatermarkExtender>
            <asp:RegularExpressionValidator ID="RegularExpressionValidator3" ControlToValidate="txtInvestmentLoan"
                runat="server" ErrorMessage="Please enter the numbers only" ValidationExpression="^[0-9]*\.?[0-9]+$"></asp:RegularExpressionValidator>
        </td>
    </tr>

    </tr>
    <tr>
        <td>Warehouse Receipt Finance</td>
        <td>

            <asp:CheckBox ID="chkWarehouseReceipt" runat="server" CssClass="check" OnChange="javascript:enableTextBox();" />
             <asp:TextBox ID="txtWarehouseReceipt" runat="server" class="txtfld-popup1" MaxLength="5" Width="100" onkeypress="if(event.keyCode<48 || event.keyCode>57)event.returnValue=false;" Enabled="false"></asp:TextBox>
            <cc1:TextBoxWatermarkExtender ID="txtWarehouseReceipt_TextBoxWatermarkExtender" runat="server" TargetControlID="txtWarehouseReceipt" WatermarkText="Amount"></cc1:TextBoxWatermarkExtender>
        </td>
    </tr>

    <tr>
        <td>Farmer Producer Companies</td>
        <td>

            <asp:CheckBox ID="chkFarmerProd" runat="server" CssClass="check" OnChange="javascript:enableTextBox();" />
            <asp:TextBox ID="txtFarmerProd" runat="server" class="txtfld-popup1" MaxLength="5" onkeypress="if(event.keyCode<48 || event.keyCode>57)event.returnValue=false;" Width="100" Enabled="false"></asp:TextBox>
            <cc1:TextBoxWatermarkExtender ID="TextBoxWatermarkExtender11" runat="server" TargetControlID="txtFarmerProd" WatermarkText="Amount"></cc1:TextBoxWatermarkExtender>
        </td>
    </tr>
</table>

Answer 1

Try:

$("#your-form").submit(function() {
   if($(this).find("#your-text").val() && $(this).find("#your-check").checked){
      $("#your-form").submit();
   }
   else{
      // not checked or empty textbox
   }
   return false;
});

Answer 2

Try using the below code:

$('#your_form_name').submit(function( event ) {
        if ($('#chkCropLoan').is(':checked') && $('#txtAmount').val() == '') {
            alert('error message');
            event.preventDefault();
        }
});

Answer 3

you don't want to submit form if Text box is Empty

just write function on submit button click event

<input type="submit" value="save" onclick="return checkvalid()" />

In script

<script type="text/javascript">
    function checkvalid() {


        if (document.getElementById('textboxId').value==""
             || document.getElementById('textboxId').value==undefined) {

            return false;
        }

</script>