Beginner value transfer across pages

[larajoseph]

hello!
I an a newbie in php. i am transfering value from one of my page to another(Mailign page) thru query string and the values gets dislayed in an input control.

Then the user enters other required values on this mailing page and then clicks submit which sends a mail. I am not able to get the query string value being passed in my mail, only this query string value goes blank in the mail though it is displayed properly in the input box when i come into this page.

i tried various options say:

if(isset($_GET)) //if 1
{
$cat = @$_GET;
}

Here, "curcategory" is the query string variable name passed from the prev page.

<input name="selcategory" type="text" disabled class="box" id="selcategory" size="32" value="<?php echo $cat; ?>">

i also tried these below given opions to get the value and then send it thru MAIL function:

//$current = $_GET;
//$current = $_REQUEST;
//$current = $HTTP_GET_VARS;
//$current = $_SESSION;

Kindly let me know whow to send this $cat thru mail using MAIL()function. I am sure i am making a big mistake sumwhere, please guide.