1 var gintStart = 0;
   2 var gintEnd = 0;
   3 var gstrLastVal = "";
   4 
   5 
   6 function findMatch() {
   7         frm1 = document.forms[0];
   8         intMatch = -1;
   9         txtLoc = frm1.elements['txtLoc'];
  10         lstLoc = frm1.elements['<%=lstLocs.ClientID%>'];
  11 
  12         var strCurText = txtLoc.value;
  13         if (strCurText.length <= gstrLastVal.length) {
  14                 // ignore all this; allow deletes gracefully
  15         } else {
  16                 //if ( gstrLastVal.length >= 2 
  17                 //&& (0 != txtLoc.value.indexOf(gstrLastVal)) ) {       
  18                 // gets rid of any hanging on autofilled text
  19                 
  20                 
  21                 if (0 != txtLoc.value.toUpperCase().indexOf(gstrLastVal.toUpperCase())) {
  22                         // txtLoc.value.slice(0, gstrLastVal.length - 1);
  23                         // then again let them do what they want.  Don't try to overcomplete
  24                         
  25                 } else {
  26                         if (txtLoc.value.length > 0) {
  27                                 // go backwards to grab the first match
  28                                 for (var i = lstLoc.options.length - 1; i >= 0; i--) {
  29 
  30                                         var strOptTxt = lstLoc.options[i].text.toUpperCase();
  31                                 
  32                                         if (0 == strOptTxt.indexOf(txtLoc.value.toUpperCase())) {
  33                                                 intMatch = i;
  34                                         }
  35                                 }
  36 
  37                                 if (-1 != intMatch) {
  38                                         lstLoc.options[intMatch].selected = true;
  39 
  40                                         txtLoc.value = lstLoc.options[intMatch].text;
  41                                         gintStart = strCurText.length;
  42                                         gintEnd = txtLoc.value.length;
  43 // (kinda ruining the whitespace to reduce width for blog)
  44 //createSelection(txtLoc,strCurText.length,txtLoc.value.length); 
  45 // it looks like this tries to set the selection while focus is 
  46 // still going to another control, blowing up the selection.
  47 // thus the delay tactics.
  48 // unsuccessful delay tactics commented, below.
  49 //backdoorSelection();
  50 //setTimeout("createSelection(txtLoc,strCurText.length,txtLoc.value.length)",100);
  51 //setTimeout("createSelection(txtLoc,4,9)",100);
  52                                         setTimeout("backdoorSelection()", 30);
  53                                 } else {
  54                                         // no match.  Deselect anything selected
  55                                         lstLoc.selectedIndex = -1;
  56                                 }
  57                         }
  58                 }
  59         }
  60         gstrLastVal = strCurText;
  61 }
  62 
  63 function backdoorSelection() {
  64         createSelection(document.forms[0].elements['txtLoc'], gintStart, gintEnd);
  65 }
  66 
  67 function createSelection(field, start, end) {
  68         if (field.createTextRange) {
  69                 var selRange = field.createTextRange();
  70                 selRange.collapse(true);
  71                 selRange.moveStart('character', start);
  72                 selRange.moveEnd('character', end);
  73                 selRange.select();
  74         } else if (field.setSelectionRange) {
  75                 field.setSelectionRange(start, end);
  76         } else if (field.selectionStart) {
  77                 field.selectionStart = start;
  78                 field.selectionEnd = end;
  79         }
  80         field.focus();
  81 }

Labels: asp.net, code, problem solved