Form:FRM1

OnChange="document.forms(2).IMG3.src=this.form.CMB1.options(this.form.CMB1.selectedIndex).value"
Form:FRM2

OnChange="document.FRM3.IMG3.src=this.form.CMB2.options(this.form.CMB2.selectedIndex).value"
Form:FRM3

OnChange="this.form.IMG3.src=this.form.CMB3.options(this.form.CMB3.selectedIndex).value"