I don't know what is wrong : I have no clue what is wrong. I would really appreciate if you could help me. I am trying to get input from the textbox, but it will not work.
I also, am having trouble getting my variables to work between functions. If anyone could help, that would be great!

    <html>
    	<head>
    		<title>Project Quiz</title>
    		<script language="JavaScript">
    			var first_name = document.getElementById('first');
    			var last_name = document.getElementById('first');
    			function firstNameClick () {
    				window.document.f.note.value = "Enter first name, then last name.";
    				window.document.f.note.size = 25;
    			}
    			function firstNameLeave () {
    				window.document.f.note.size = 10;
    				window.document.f.note.value = "";
    				first_name = document.getElementById('first');
    				if ((first_name != "") && (last_name != "")) {
    					window.document.f.firstDisplay.value=(first_name);
    					window.document.f.firstDisplay.value=(last_name);
    				} else {
    					window.document.f.firstDisplay.value="";
    				}
    
    			}
    			
    			function lastName () {
    				last_name = document.getElementById('last');
    				if ((first_name != "") && (last_name != "")) {
    					window.document.f.lastDisplay.value=(last_name);
    					window.document.f.firstDisplay.value=(first_name);
    				} else {
    					window.document.f.lastDisplay.value="";
    				}
    			}
    			
    		</script>
    	</head>
    	<body>
    		<form name="f">
    			<font>First Name</font>
    			</br>
    			<input type="text" id="first" name="first" size=35 onClick="firstNameClick();" onBlur="firstNameLeave();">
    			</br>
    			</br>
    			<font>Last Name</font>
    			</br>
    			<input type="text" id="last" name="last" size=35 onBlur="lastName();">
    			</br>
    			</br>
    			<font>Note</font>
    			</br>
    			<input type="text" name="note" size=10 value="" readonly>
    			</br>
    			</br>
    			<font>Display</font>
    			</br>
    			<input type="text" name="firstDisplay" size=25 value="" readonly>
    			</br>
    			<input type="text" name="lastDisplay" size=25 value="" readonly>
    			
    		</form>
    	</body>
    </html>