Prevent selection of Lookup values on save

When you have a Lookup column you may find some results you don’t want your end users to select, for instance in my example below, the column name is ‘Team Name’ which is also a required field. This column basically shows every single team.

What the script below does is prevents the user from saving the form if “Human Resources” or “–Select a Team–” have been chosen. It also provides text under the specific column to show an error message “Please select a different Team”. (last section of the code below to see where to place this).

The code below can be amended to be a Choice column rather than a lookup by changing the getTagFromIdentifierAndTitle(“select”,”Lookup”,”Team Name Required Field”); to your column.

<script>

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;
}

function PreSaveAction(){
var oTeamName = getTagFromIdentifierAndTitle(“select”,”Lookup”,”Team Name Required Field”);
var blockName = oTeamName.options[oTeamName.selectedIndex].text;

if(blockName.indexOf(‘–Choose a Team–‘)==0||blockName.indexOf(‘Human Resources’)==0){
alert(“Please select a different Team”);
$(“#tname-error”).text(“Please select a different Team”);
return false;
}
return true;
}

</script>

<td width=”400px” valign=”top” class=”ms-formbody”>
<SharePoint:FormField …….
<span id=”tname-error”></span>
<SharePoint:FieldDescription ……

Details below of the tags & identifiers per column type

Column Type Tag Identifier
Single Line of Text input text
Multiple Line of Text input textarea
Lookup select Lookup