textEntryPlaceholder.js

/* This will work for any text entry except the forms */

Qualtrics.SurveyEngine.addOnload(function() {
	var qid = this.questionId;
	var placeholderText = 'I am different text';
	jQuery('#' + qid + ' input[type="text"], #' + qid + ' textarea').attr('placeholder',placeholderText);
});

/* 
This will work on a Form question (where there are multiple inputs)
You will need to copy this format if you have more than 3 text boxes
*/

Qualtrics.SurveyEngine.addOnload(function() {
	var placeholder1 = 'my text';
	var placeholder2 = 'my other text';
	var placeholder3 = 'some more text';
  // create more placeholder text variables as necessary and assign below
	
	var qid = this.questionId;
	// note that the index is different for each box. Because it's an array, the first input 
  // will be 0, the second, 1, and so on. 
	jQuery('#' + qid + ' .InputText')[0].setAttribute('placeholder',placeholder1);
	jQuery('#' + qid + ' .InputText')[1].setAttribute('placeholder',placeholder2);
	jQuery('#' + qid + ' .InputText')[2].setAttribute('placeholder',placeholder3);

});