attempt to add pref option

code/modules/client/preference/preferences.dm

@@ -93,6 +93,7 @@ var/global/list/special_role_times = list( //minimum age (in days) for accounts
 	var/show_ghostitem_attack = TRUE
 	var/UI_style_color = "#ffffff"
 	var/UI_style_alpha = 255
+	var/windowflashing = TRUE
 
 
 	//character preferences
@@ -418,6 +419,7 @@ var/global/list/special_role_times = list( //minimum age (in days) for accounts
 			dat += "<h2>General Settings</h2>"
 			dat += "<b>Fancy NanoUI:</b> <a href='?_src_=prefs;preference=nanoui'>[(nanoui_fancy) ? "Yes" : "No"]</a><br>"
 			dat += "<b>Ghost-Item Attack Animation:</b> <a href='?_src_=prefs;preference=ghost_att_anim'>[(show_ghostitem_attack) ? "Yes" : "No"]</a><br>"
+			dat += "<b>Window Flashing:</b> <a href='?_src_=prefs;preference=winflash'>[(windowflashing) ? "Yes" : "No"]</a><br>"
 			dat += "<b>Custom UI settings:</b><br>"
 			dat += " - <b>UI Style:</b> <a href='?_src_=prefs;preference=ui'><b>[UI_style]</b></a><br>"
 			dat += " - <b>Color:</b> <a href='?_src_=prefs;preference=UIcolor'><b>[UI_style_color]</b></a> <table style='display:inline;' bgcolor='[UI_style_color]'<tr><td>__</td></tr></table><br>"
@@ -1935,6 +1937,9 @@ var/global/list/special_role_times = list( //minimum age (in days) for accounts
 				if("ghost_att_anim")
 					show_ghostitem_attack = !show_ghostitem_attack
 
+				if("winflash")
+					windowflashing = !windowflashing
+
 				if("UIcolor")
 					var/UI_style_color_new = input(user, "Choose your UI color, dark colors are not recommended!", UI_style_color) as color|null
 					if(!UI_style_color_new) return

code/modules/client/preference/preferences_mysql.dm

@@ -14,7 +14,8 @@
 					nanoui_fancy,
 					show_ghostitem_attack,
 					lastchangelog,
-					exp
+					exp,
+					windowflashing
 					FROM [format_table_name("player")]
 					WHERE ckey='[C.ckey]'"}
 					)
@@ -42,6 +43,7 @@
 		show_ghostitem_attack = text2num(query.item[12])
 		lastchangelog = query.item[13]
 		exp = query.item[14]
+		windowflashing = text2num(query.item[15])
 
 	//Sanitize
 	ooccolor		= sanitize_hexcolor(ooccolor, initial(ooccolor))
@@ -57,6 +59,7 @@
 	show_ghostitem_attack = sanitize_integer(show_ghostitem_attack, 0, 1, initial(show_ghostitem_attack))
 	lastchangelog	= sanitize_text(lastchangelog, initial(lastchangelog))
 	exp	= sanitize_text(exp, initial(exp))
+	windowflashing = sanitize_integer(windowflashing, 0, 1, initial(windowflashing))
 	return 1
 
 /datum/preferences/proc/save_preferences(client/C)