[jQuery] Validation Error message help

[jQuery] Validation Error message help

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<DIV><FONT size=2 face="Trebuchet MS"><SPAN class=547330816-11082009>I have this
script:</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009></SPAN></FONT> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>$(document).ready( function() {</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>    $('#username').blur( function ()
{</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>        fieldName =
$(this).attr('id');<BR>        fieldValue =
$(this).val();</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>       
$.post('/users/ajax_validate',
{<BR>                                       
field:
fieldName,<BR>                                       
value:
fieldValue<BR>                                       
},<BR>              
function(error) {</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>                  
if(error.length != 0)
{               
</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>                      
$('#username').after('<div class="error-message" id="'+ fieldName
+'-exists">' + error +
'</div>');<BR>                  
}<BR>                  
else
{<BR>                      
$('#' + fieldName +
'-exists').remove();<BR>                  
}<BR>              
});<BR>     });   </SPAN></FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>});</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009></SPAN></FONT> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN class=547330816-11082009>So when the
user leaves the field it checks validation. If error it shows an error message.
Everything is working fine except if the user goes back to the field where there
was an error and does not chnge anything and leaves the field again the error
message is duplicated.</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009></SPAN></FONT> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN class=547330816-11082009>So they
enter a username peter it says "Please choose a different name" if they go back
to the username and thenleavewith out changing "peter" i now
have:</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009> "Please choose a different
name"</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN class=547330816-11082009>"Please
choose a different name"</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009></SPAN></FONT> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN class=547330816-11082009>What do I
have to change / add so that only 1 message will appear?</SPAN></FONT></DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009></SPAN></FONT> </DIV>
<DIV><FONT size=2 face="Trebuchet MS"><SPAN
class=547330816-11082009>Thanks</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV align=left><FONT size=2 face=Arial>Dave </FONT></DIV></BODY></HTML>