why doesn't javascript arrangement endorse box?

i am perplexing repair bugs product i inherited, i have dash javascript ostensible hilight integrate boxes cocktail adult endorse box. now happens i boxes change tone there 5 second delay, following it's blank endorse only accepts itself. does anyone smarter i anything erroneous code?

function lastcheckinv() {

    document.getelementbyid("ctl00$contentplaceholdermain$indet$txtinvnumber").style.background = "yellow";
    document.getelementbyid("ctl00$contentplaceholdermain$indet$txtinvnumber").focus();
    document.getelementbyid("ctl00_contentplaceholdermain_indet_addcharges").style.background = "yellow";
    document.getelementbyid("ctl00_contentplaceholdermain_indet_lblfreight").style.background = "yellow";
    bretval = confirm("are certain information compared check correct?");

    relapse bretval;

}