Input text form, using javascript to clear and restore form contents problem

I have this line of HTML

<input type="text" name="addQty" size="1" 
       class="addQty" value="0" 
       onclick="$(this).val('')" 
       onblur="itmQtyChk($(this).val())" />

the itmQtyChk function does this:

function itmQtyChk( qty ) {
    if( qty == "") {
        $(this).val("0");
    } else {
        $(this).val(qty);
    }
 }

My problem is I want it to return the original value to the input text if they exit the field and don't change anything开发者_StackOverflow中文版, but it is not working.

Thank you for any help.

---

this in itmQtyChk function is not referring to the input but to the window object.

Change the function to accept the input as parameter:

function itmQtyChk(input) {
    if (input.val() == "") {
        input.val("0");
    }
    // the else part is not needed
}

with the onblur event also:

onblur="itmQtyChk($(this))"

---

Check this fiddle, it has lots of room for improvement, but it can help you:

http://jsfiddle.net/eDuKr/1/

$(function(){

    var cacheQty;

    $('.addQty').click(function(){
        cacheQty = $(this).val();
        $(this).val('');

    }).blur(function(){
        if ($(this).val() === ''){
            $(this).val(cacheQty);
        }else{
            cacheQty = $(this).val();
        }
    });   
});