[amibroker] Code Help

["tipequity" <l3456@xxxxxxxxxx>]

I have written the following code to plot % chg in price of ticker 
from starting date to ending date (using parameters). I have to 
problems:
1. when I change the date it crashes, point to from date in the title.
2. when it works, it draws a horizontal line from first visible bar 
to the starting date. I want to eliminate this line. TIA

dt=DateTime();
StartDate = ParamDate ( "Start Date" , Date () ); 
EndDate = ParamDate ( "End Date" , Date () ); 
StartDateBar = LastValue(ValueWhen ( DateNum () == StartDate, 
BarIndex ())); 
EndDateBar = LastValue(ValueWhen( DateNum () == EndDate, BarIndex 
() )); 

Ticker = 0;

for (Bar = StartDateBar; Bar < EndDateBar-1; Bar++)
{
ticker[bar] =  100 *(( C[Bar] - C[ StartDateBar ])/C[StartDateBar ]);
//_TRACE("Bar: " + Bar + " StartDateBar " + C[ StartDateBar ] + " C
[Bar] " + C[Bar]);
}
Plot( ticker, Name(), colorBlue );

SetChartOptions( 1, chartShowDates );
PlotGrid( 0, colorYellow );
Title = "From: " + WriteVal(dt[StartDateBar],formatDateTime) + " 
To: " + Date() + " - " + "{{VALUES}}"  + "\n" + 
		Interval(2) + " - " + _DEFAULT_NAME();


------------------------------------

Please note that this group is for discussion between users only.

To get support from AmiBroker please send an e-mail directly to 
SUPPORT {at} amibroker.com

For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG:
http://www.amibroker.com/devlog/

For other support material please check also:
http://www.amibroker.com/support.html
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/amibroker/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/amibroker/join
    (Yahoo! ID required)

<*> To change settings via email:
    mailto:amibroker-digest@xxxxxxxxxxxxxxx 
    mailto:amibroker-fullfeatured@xxxxxxxxxxxxxxx

<*> To unsubscribe from this group, send an email to:
    amibroker-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/