Javascript help

[BliarOut]

I have the following JS that puts the value of a select list into a text box called SURGEON on a form. It's called from the "onchange = putsur1()" property of the select list sur1

JS starts....
//Added by RB to get info from drop down select lists into text boxes.
function putsur1()
{
txt=document.forms[0].sur1.options[document.forms[0].sur1.selectedIndex].value
document.forms[0].SURGEON.value=txt
}
JS ends.....

However, on occasion the value returned is blank, ie they don't have an e-mail address set in MySQL. If the value returned is blank, then I want to put the text of the select list in the box instead.

Any ideas how I would do this? I know I need to test the result of [document.forms[0].sur1.selectedIndex].value to see if it's null and if it is use [document.forms[0].sur1.selectedIndex].text instead, but I'm not familiar with JS to know the syntax and where to insert it.

TAI

[docevi1]

does this work? Not too familiar with JS and if txt=="" is the correct syntax, might be null.

//Added by RB to get info from drop down select lists into text boxes.
function putsur1()
{

txt=document.forms[0].sur1.options[document.forms[0].sur1.selectedIndex].value

if(txt==""
{
txt=document.forms[0].sur1.selectedIndex
}
document.forms[0].SURGEON.value=txt

}

>> Edited by docevi1 on Friday 5th August 15:38

[BliarOut]

Close enough.... And certainly a big help. I ended up with:


JS Starts....

//Added by RB to get info from drop down select lists into text boxes.
function putsur1()
{

txt=document.forms[0].sur1.options[document.forms[0].sur1.selectedIndex].value

if(txt==""
{
txt=document.forms[0].sur1.options[document.forms[0].sur1.selectedIndex].text
}
document.forms[0].SURGEON.value=txt
}

JS ends....

Thanks

[GreenV8S]

I suspect you want something like:

function putsur1()
{
var sur1 = document.forms[0].sur1;
var txt = sur1.options[sur1.selectedIndex].value;
if((txt == null) || (text=="" ))
{
txt = sur1.options[sur1.selectedIndex].text;
}

document.forms[0].SURGEON.value=txt;
}

Edit: beaten to it!

>> Edited by GreenV8S on Friday 5th August 16:01

[BliarOut]

Interesting... Is || an OR operator in JS?

[DanL]

BliarOut said:

Interesting... Is || an OR operator in JS?

Yes. Exclusive or, no less, so if one side is true it doesn't bother evaluating the other side...

Dan

[BliarOut]

Ooh, XOR, nice!

Thanks for the help guys.

[scorp]

DanL said:

BliarOut said: Interesting... Is || an OR operator in JS? Yes. Exclusive or, no less, so if one side is true it doesn't bother evaluating the other side... Dan

[pedant]
I believe thats called a lazy evaluator (dropping out of the test earlier so the right side doesnt get evaluated if the left side is true). The C programming language works the same way.

Exclusive OR would be if both sides are true then the result would be false (true XOR true = false, true OR unknown = true).

[robbieduncan]

scorp said:

[pedant] I believe thats called a lazy evaluator (dropping out of the test earlier so the right side doesnt get evaluated if the left side is true). The C programming language works the same way. Exclusive OR would be if both sides are true then the result would be false (true XOR true = false, true OR unknown = true).

Just what I was about to say. Java works the same way too (for ANDs as well). In fact pretty much any well designed language does. No idea about VB though!