December 28, 2000 - Visibility Assignment in STYLE

Yehuda Shiran December 28, 2000
Visibility Assignment in STYLE
Tips: December 2000

Yehuda Shiran, Ph.D.
Doc JavaScript

When you assign values to the STYLE attribute, do not box them inside quotes -- these are not strings. The visibility property is a good example. Here is an HTML code for a button. Notice that the visibility's value is visible and it is not enclosed in quotes:

<INPUT ID="button1" STYLE="position:relative; left:250px; visibility:visible;" 
TYPE="button" VALUE="Show My Visibility" onclick="handleClick1()">

Here is how this button renders:

When you click this button, you get that the visibility of the button is "visible". When you enclose visible in quotes above, JavaScript won't recognize it, and will return an empty string. Here is such a button definition:

<INPUT ID="button2" STYLE="position:relative; left:250px; visibility:'visible';" 
TYPE="button" VALUE="Show My Visibility" onclick="handleClick2()">

Go ahead and find the button's visibility:

Internet Explorer is forgiving and will return "visible". Netscape 6 is not so forgiving and will return an empty string. Only when you handle visibility values in JavaScript, they convert into strings, so you can easily manipulate them.