use this. in function

Currently, I am doing this.

<input type="text" id="login_email" value="Email" onfocus="if(this.value==this.defaultValue){this.value=''}"/>

Code (markup):

And would like to place this "onfocus" code in a function, but I haven't managed to find how to do this. stuff for whatever called the function.

I was kind of thinking I needed to do something like this.

<script type="text/javascript">
	function clear_input(trigger){
		var obj = document.getElementById[trigger];
		if(obj.value==obj.defaultValue){
			obj.value="";
		}
	}
</script>
<input type="text" id="login_email" onfocus="clear_input(this.id)"/>

Code (markup):

But I wasn't quite sure about the "this.id" part, or if there was an easier method. Thanks.

 

got it thanks anyway

apparently, I can send "this" as a whole to the function

 

the better way to do things is to avoid inline onfocus= within the elements.

i think you can assign the events in a more semantic way, at which point the function will have 'this' refer to the calling element

document.getElementById("login_email").onfocus = function(e) {
    // 'this' now is automatically the login_email object, so you can do. 
    var defaultValue = this.getAttribute("defaultValue");
...
}

PHP:

in an ideal world, write a css selector that goes through, say all input.required and applies the function to them.
'e' should contain a reference to the event itself, useful if you want to stop it or whatever.

i hope this helps

 

yeah i was thinking about that, but then i didn't want to spend too much time on it, because I only have about 10 inputs.

thanks for the tips