Change background color with function 1

[tabbytab]

Hi guys

I am totally new to javascript so excuse the crumby code....

I am trying to change the background color of an input box when a radio button is clicked.

I am successfully changing the text in the input box when the radio button is clicked but have no idea as to syntax to change color.

The input box controlname and text value are passed to the function which allows me to reuse the function.

function J(QName,SelectedValue)
{
if (QName.substr(1,1) =="A")
eval('document.forms[0].RA'+(QName.substr(2,(QName.length)-2))+'.value=SelectedValue');

if (QName.substr(1,1) =="B")
eval('document.forms[0].RB'+(QName.substr(2,(QName.length)-2))+'.value=SelectedValue');
}

I've tried

function J(QName,SelectedValue)
{
if (QName.substr(1,1) =="A")
eval('document.forms[0].RA'+(QName.substr(2,(QName.length)-2))+'.value=SelectedValue');

eval('document.forms[0].RA'+(QName.substr(2,(QName.length)-2))+'.style.backgroundcolor="#000000"');


if (QName.substr(1,1) =="B")
eval('document.forms[0].RB'+(QName.substr(2,(QName.length)-2))+'.value=SelectedValue');
}

Any pointers

Many thanks in advance
TabbyTab

 

[BillyRayPreachersSon]

I'd go with this:

function J(QName,SelectedValue) {
	var frm = document.forms[0].elements;
	if (QName.substr(1,1) == 'A') {
		frm['RA' + QName.substr(2, QName.length - 2)].value = SelectedValue;
		frm['RA' + QName.substr(2, QName.length - 2)].style.backgroundColor = '#000000';
	}

	if (QName.substr(1,1) == 'A') {
		frm['RB' + QName.substr(2, QName.length - 2)].value = SelectedValue;
		frm['RB' + QName.substr(2, QName.length - 2)].style.backgroundColor = '#000000';
	}
}

When has the added benefit of removing the use of eval (which is always best avoided).

Hope this helps,
Dan

[tt]Dan's Page [blue]@[/blue] Code Couch

http://www.codecouch.com/dan/

[/tt]

 

[BillyRayPreachersSon]

Ok - minor typo in that second bit (== 'A' should be == 'B')... but if the radio you are selecting is always asscoiated with the letter, you could actually get away with even less code:

function J(QName, SelectedValue) {
	var frm = document.forms[0].elements;
	var letter = QName.substr(1, 1);
	
	frm['R' + letter + QName.substr(2, QName.length - 2)].value = SelectedValue;
	frm['R' + letter + QName.substr(2, QName.length - 2)].style.backgroundColor = '#000000';
}

Dan

[tt]Dan's Page [blue]@[/blue] Code Couch

http://www.codecouch.com/dan/

[/tt]

 

[BillyRayPreachersSon]

Or even:

function J(QName, SelectedValue) {
	var radio = document.forms[0].elements['R' + QName.substr(1, QName.length - 2)];
	radio.value = SelectedValue;
	radio.style.backgroundColor = '#000000';
}

and if QName begins with "R", you could use:

function J(QName, SelectedValue) {
	var radio = document.forms[0].elements[QName.substr(0, QName.length - 2)];
	radio.value = SelectedValue;
	radio.style.backgroundColor = '#000000';
}

I'm sure you get the idea by now ;-)

Dan



[tt]Dan's Page [blue]@[/blue] Code Couch

http://www.codecouch.com/dan/

[/tt]

 

[tabbytab]

Cool - many thanks for that - it works a treat.

I guess I have a lot to learn!

TabbyTab