There are occasions when we need to pre-populate SharePoint fields with data, such as from a query string. the solution is not that difficult, using a bit of Javascript. Paul blogged the solution of at Autosponge.
(Code below copied from Autosponge and full credit to Paul)
[code:html]
<script type="text/javascript">
// This javascript sets the default value of a lookup field identified
// by <<FIELD DISPLAY NAME>> to the value stored in the querysting variable
// identified by <<QUERYSTRING VARIABLE NAME>>
// Customize this javascript by replacing <<FIELD DISPLAY NAME>> and
// <<QUERYSTRING VARIABLE NAME>> with appropriate values.
// Then just paste it into NewForm.aspx inside PlaceHolderMain
_spBodyOnLoadFunctionNames.push("fillDefaultValues");
function fillDefaultValues() {
var qs = location.search.substring(1, location.search.length);
var args = qs.split("&");
var vals = new Object();
for (var i=0; i < args.length; i++) {
var nameVal = args[i].split("=");
var temp = unescape(nameVal[1]).split('+');
nameVal[1] = temp.join(' ');
vals[nameVal[0]] = nameVal[1];
}
setLookupFromFieldName("<<FIELD DISPLAY NAME>>", vals["<<QUERYSTRING VARIABLE NAME>>"]);
setTextFromFieldName("<<FIELD DISPLAY NAME>>", vals["<<QUERYSTRING VARIABLE NAME>>"]);
setPeoplePicker("People Picker", vals["<<QUERYSTRING VARIABLE NAME>>"]);
//do not change the fieldname for setPeoplePicker
}
function setTextFromFieldName(fieldName, value) {
if (value == undefined) return;
var theInput = getTagFromIdentifierAndTitle("input","",fieldName);
theInput.value=value;
}
function setPeoplePicker(fieldName, value) {
if (value == undefined) return;
var assignedToInput = getTagFromIdentifierAndTitle("div", "",fieldName);
assignedToInput.innerHTML = value;
}
function setLookupFromFieldName(fieldName, value) {
if (value == undefined) return;
var theSelect = getTagFromIdentifierAndTitle("select","Lookup",fieldName);
// if theSelect is null, it means that the target list has more than
// 20 items, and the Lookup is being rendered with an input element
if (theSelect == null) {
var theInput = getTagFromIdentifierAndTitle("input","",fieldName);
ShowDropdown(theInput.id); //this function is provided by SharePoint
var opt=document.getElementById(theInput.opt);
setSelectedOption(opt, value);
OptLoseFocus(opt); //this function is provided by SharePoint
} else {
setSelectedOption(theSelect, value);
}
}
function setSelectedOption(select, value) {
var opts = select.options;
var l = opts.length;
if (select == null) return;
for (var i=0; i < l; i++) {
if (opts[i].value == value) {
select.selectedIndex = i;
return true;
}
}
return false;
}
function getTagFromIdentifierAndTitle(tagName, identifier, title) {
var len = identifier.length;
var tags = document.getElementsByTagName(tagName);
for (var i=0; i < tags.length; i++) {
var tempString = tags[i].id;
if (tags[i].title == title && (identifier == "" || tempString.indexOf(identifier) == tempString.length - len)) {
return tags[i];
}
}
return null;
}
</script>
[/code]
To get the code onto the page, we simply add a Content Editor Web Part onto Newform.aspx , or whichever page we have the fileds on