Added GetValue method that takes care of missing parameters.

git-svn-id: http://yate.null.ro/svn/yate/trunk@542 acf43c95-373e-0410-b603-e72c3f656dc1

scripts/libyate.php

@@ -159,6 +159,19 @@ class Yate
 	$this->params=array();
     }
 
+    /**
+     * Retrive the value of a named parameter
+     * @param $key Name of the parameter to retrive
+     * @param $defvalue (optional) Default value to return if parameter is not set
+     * @return Value of the $key parameter or $defvalue
+     */
+    function GetValue($key, $defvalue = null)
+    {
+	if (isset($this->params[$key]))
+	    return $this->params[$key];
+	return $defvalue;
+    }
+
     /**
      * Fill the parameter array from a text representation
      * @param $parts A numerically indexed array with the key=value parameters