Hello
I need to automatically set form field with value passed by url.
For example: user clicks link .....?var1=sometext
and form displays and one of fields has already value "sometext' form var1.
How can i do it?

Link to how to docs here

Documentation is correct but not complete.

You can use a PHP script in default value to retrieve info from a database (see also example 4 in www.rsjoomla.com/support/documentation/r...n-form-is-shown.html). But how to use the passed parameter value in this query?

Ok, first pass the value in the url such as 'www.mywebsite.com/index.php?option=com_rsform&formId=2&form[name_of_field]=value

in the destination form if the field name is the same in both forms it will contain the value you passed in the url. If the destination form field has a diffeent name you will need to get the value into it. Use 'php scripts - pre-processing and enter something like this where value form 2 = value form 1

I think I didn't explain very well my problem.

Passing a parameter from one form to another works fine if you just have to put that value in a field. But what I want to do, is use this parameter as a key for a query to get another fields default value.

//<code>
$db = JFactory::getDbo();
$db->setQuery("SELECT `column_name` FROM `#__table_name` WHERE `column_name`='value' LIMIT 1");
return $db->loadResult();
//</code>

in this example: how to achieve that "value' becomes the passed parameter?

assign the value to a variable and use that in your query