Well I feel like an idiot, because its simple and I cant get it to work I am a jscript newb..... I have a form with billing and shipping addresses. If they choose a country other than USA then it replaces the billing state field with the billing alternate state field. I then try to check that in the jscript function I created to copy the billing address to shipping address if they click the copy address function.

Below you see the bstate_value code which is obviously wrong, the odd thing is... it will copy the alternate state values when I have it like this. Syntactical error I caught... Anyways if I fix that to be f.bstate.value || etc it will for the bstate but not alt state.

If this is confusing I can put in the code that I think should work but is not.

form fields are

bstate, sstate, balt_state, salt_state

function cbilling(f) {
  if(f.usebilling.checked == true) {		  
    f.saddr1.value = f.baddr1.value;
	f.scity.value = f.bcity.value;
	f.szipc.value = f.bzipc.value;
	if (!f.bstate_value || 0 === f.bstate_value.length){
	  f.salt_state.value = f.balt_state.value;
	} else {
		f.sstate.value = f.bstate.value;
	}
	
  }
}

thanks in advance

Well I feel like an idiot,

Hang on, I'll see if I can find you one. We do have a few to spare most days.

Your logic on this !f.bstate_value may be a little flawed, depending on where the value comes from, checking for to be true || false may not give the results you are expecting.

http://www.mapbender.org/JavaScript_...undefined,_NaN

I needed that laugh this morning.

if (!f.bstate_value || 0 === f.bstate_value.length){

needs to be this

if (!f.bstate.value || 0 === f.bstate.value.length){

These are form elements and in the case that someone sets the country to a non US country I refresh the form and remove bstate swapping it out for free form balt_state so that the user can put in their own value

In the jscript I am then trying to say, if there is no value in bstate then use balt_state to copy to salt_state

Based on the link you sent, I would have thought that the === would have caught an undefined variable in this case

yep but the === is applied to the length so if there was even a space in the field it would be true.

it is the "if NOT f.bstate.value" where the error is, you are using a string value as a boolean which doesn't always work. I could put true in that field and your logic would accept it, because length would be greater than zero and the value would NOT be false.

If you are checking for an empty string then check for ''

in all actuality the field wont even be on the form when this function is called. I am removing it with php based on their choice of country. If USA there is a bstate field else its balt_state. Is checking for an empty string the proper way to handle that?

It it doesn't exist in the form checking for a value will throw an exception.
use

if (document.getElementById(id) != null)

to test if the element actually exists before trying to get the value.

got it. thanks a ton for the help.