html - img tag without src attribute but with class attribute gives a random display -

i come across 1 question in stackoverflow user want give icon in html, not using

<img src="smiley.gif" alt="smiley face" width="42" height="42">

but, using class like

<img class="iconclass">

and css class is

.iconclass{               background:url('smiley.gif')!important;           }

i tried this, works me, wierd thing that, image getting repeated till width , height specified. why happening, , how solve it?

image output

background repeat default set repeat. should set:

.iconclass{    background-repeat: no-repeat; }

or :

.iconclass{               background:url('smiley.gif')!important no-repeat;           }

My