//FUNCIO OBRI FINESTRES CENTRADES

function openwin(P_url,P_w,P_h,P_scroll){
	var win_id=parseInt(Math.random()*2000)
	var p_url=check_null_values(P_url,P_url,0);
	var p_w=check_null_values(P_w,P_w,400);
	var p_h=check_null_values(P_h,P_h,300);
	var p_scroll=check_null_values(P_scroll,'yes','no');
	
	
	var left_point = parseInt(window.screen.availWidth/2)-(p_w/2); 
	var top_point = parseInt(window.screen.availHeight/2)-(P_h/2); 

NewWindow=window.open(p_url,'win_'+win_id,'width='+p_w+',height='+p_h+',left='+left_point+',top='+top_point+',toolbar=No,location=No,scrollbars='+p_scroll+',status=No,resizable=No,fullscreen=No'); 
	NewWindow.focus(); 
}

function check_null_values(P_value,P_return,P_no_return){
	if(P_value){
		return P_return;
	}else{
		return 
		P_no_return;
	}
}