Accessing form elements dynamically

[EvrimAgha]

Hi

I am using an external JavaScript file that should handle number of similar forms and form elements on different html pages.

What I need to do is , pass the name of the form, the two text boxes , name of a combobox and a checkbox group to the file.

As an example , inside Webpage I have:

< body onload="javascript:runMyCode('myform1','textbox1','textbox2','checkgroup1','combo1')">

and the external file has the following code:

function runMyCode(form,name,job,check,cbo) 
{
document.getElementById(form).getElementById(name).value='value1';
document.getElementById(form).getElementById(job).value='value2';
.....

}

But it is wrong and I am hoping JavaScript experts will help me solve this. Kindly tell me how to go about this.


Thank you in advance
Evrim

[Dasty]

Function getElementById is method of document element. You can not call it on "form" DOM element. But, why dont you just call it that way?

function runMyCode(form,name,job,check,cbo)
{
  document.getElementById(name).value='value1';
  document.getElementById(job).value='value2';
}

Two different elements can not have same id in valid page. But don't forget to set id properties to them. like:

[HTML]<input type=text id=myid1 .......... >[/HTML]

[EvrimAgha]

Function getElementById is method of document element. You can not call it on "form" DOM element. But, why dont you just call it that way?

function runMyCode(form,name,job,check,cbo)
{
  document.getElementById(name).value='value1';
  document.getElementById(job).value='value2';
}

Two different elements can not have same id in valid page. But don't forget to set id properties to them. like:

[HTML]<input type=text id=myid1 .......... >[/HTML]

Thank you very much for your reply ....

Could you please tell me how it is possible to access the form element itself?
For example:

function goPlaces(theForm,theURL){
    document.theForm.action=theURL;
    document.theForm.submit();
}

Generates errors ...........


Thanks again
Evrim

[Dasty]

function goPlaces(theForm,theURL)
{
  document.theForm.action=theURL;
  document.theForm.submit();
}

You are sending theForm attribute as string. And you can not use string that way. But you was close. Use this instead:

function goPlaces(theForm,theURL)
{
  document[theForm].action=theURL;
  document[theForm].submit();
}

Dont forget that in this case "theForm" string is name (not id) of the form element.

But you can access it by id too:

document.getElementById('id_of_form_element').action

And you have 'forms' array in document element as well:

document.forms[0].action

Choose whatever you want. (but I prefer referencing any elements by id)

[EvrimAgha]

You are sending theForm attribute as string. And you can not use string that way. But you was close. Use this instead:

function goPlaces(theForm,theURL)
{
  document[theForm].action=theURL;
  document[theForm].submit();
}

Dont forget that in this case "theForm" string is name (not id) of the form element.

But you can access it by id too:

document.getElementById('id_of_form_element').action

And you have 'forms' array in document element as well:

document.forms[0].action

Choose whatever you want. (but I prefer referencing any elements by id)

Thank you for helping me :-)