show textbox when checkbox is checked

there is big mistake, ID of requiredfield is in correct

$(function () {
            if ($("[id*='chkexamination']").is(":checked")) {
                $("[id*='chkremarks']").show();
            }
         

ValidatorEnable($("[id*='RequiredFieldValidator4']")[0], $("[id*='chkexamination']").is(":checked")); //correct ID

                ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']").is(":checked")); //incorrect ID

        })
        $("[id*='chkexamination']").click(function () {
            if ($(this).is(":checked")) {
                $("[id*='chkremarks']").show();
                ValidatorEnable($("[id*='RequiredFieldValidator4']")[0], $("[id*='chkexamination']").is(":checked")); //correct ID

                ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']").is(":checked")); //incorrect ID

            }
            else {
                $("[id*='chkremarks']").hide();
               

ValidatorEnable($("[id*='RequiredFieldValidator4']")[0], $("[id*='chkexamination']").is(":checked")); //correct ID

                ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']").is(":checked")); //incorrect ID

            }
        }
        );

i have one checkbox i.e. if checkbox is checked then textbox show oherwise hiddden
and on button Save if checkbox is unchecked then required field validator must be disable
Whether Further Examination Required:
                     
                   

                   

                   

i tryed and tested each one of your solution but i dont find where is the problem

now, error is

id is not defined

There is no [0].is in my updated code, you copied from my earlier replies, please check the latest one. Copy from sept 21st reply

getting an error in while i see in console

$(...)[0].is is not a function

@Garima, Test this 

$(function()
{
if($([id*='chkexamination']).is(":checked"))
{
  $("[id*='chkremarks']").show();
} 
ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']")[0].is(":checked"));  
})

$("[id*='chkexamination']").click(function () 
{
if ($(this).is(":checked")) 
{
$("[id*='chkremarks']").show();
ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']")[0].is(":checked"));
} 
else 
{
$("[id*='chkremarks']").hide();
ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']")[0].is(":checked"));
}
}
);

Sachin Singh

by applying your updated code, now hidden textbox is not visible

Give it a try

$(function()
{
if($([id*='chkexamination'])[0].is(":checked")){$("[id*='chkremarks']")[0].show();
ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']")[0].is(":checked"));}   })
$("[id*='chkexamination']").click(function () 
{
if ($(this).is(":checked")) 
{$("[id*='chkremarks']")[0].show();
}
else {$("[id*='chkremarks']")[0].hide();
}
ValidatorEnable($("[id*='chkremarks']")[0], $("[id*='chkexamination']")[0].is(":checked"));
}
);

If you will remove then it will not be  a required field even when checkbox is checked. However save will start working.

    Whether Further Examination Required:
                     
                   

                   

                   

$(function () {
            if ($([id *= 'chkexamination']).is(":checked")) {
                $("[id*='chkremarks']").show();
                ValidatorEnable($("[id*=chkremarks]"),
                    $("[id*=chkexamination]").is(":checked"));
            }
        })
        $("[id*='chkexamination']").click(function () {
            if ($(this).is(":checked")) {
                $("[id*='chkremarks']").show();
            }
            else {
                $("[id*='chkremarks']").hide();
            }
            ValidatorEnable($("[id*=chkremarks]"), $("[id*=chkexamination]").is(":checked"));
        }
        );
        
i use this , but not working

can i remove required field validtor ?

@Garima, you need to do this to disable the validator

$(function()
{if($([id*='chkexamination']).is(":checked")){$("[id*='chkremarks']").show();ValidatorEnable($("[id*=chkremarks]"), $("[id*=chkexamination]").is(":checked"));}   })
$("[id*='chkexamination']").click(function () 
{
if ($(this).is(":checked")) 
{
   $("[id*='chkremarks']").show();
}
else {
  $("[id*='chkremarks']").hide();
}
ValidatorEnable($("[id*=chkremarks]"), $("[id*=chkexamination]").is(":checked"));
}
);

                  Required

as i use required field validator, senerio is when textbox hidden then requiredfield validator is enale

Sachin Singh

there is a problem, when i dont need any data insert in textbox then its data is not saving

@Garima your answer is wrong , if in the first load your checkbox will be checked (suppose for edit) then also div will not display, until you uncheck the checkbox.

Use below code

1. For page load

2.For checkbox check

add below lines of code

$(function()
{
if(
$([id*='chkexamination']).is(":checked")){$("[id*='chkremarks']").show();
}   
})
$("[id*='chkexamination']").click(function () {if ($(this).is(":checked")) 
{
$("[id*='chkremarks']").show();} else {$("[id*='chkremarks']").hide();
}
}
);

its done,

i use the property

the way i am using its working but i want it when page open

Try this