jquery not working on iphone

Hello,
I am adding this code to remove the blank option for the drop down list. Additionally, the code must leave the drop down with no default options.( keeping it blank before it is selected, and not showing the blank box when the drop down is clicked)
this is the code added in the Onload function:
jQuery("#"+this.questionId+" select").find("option:eq(0)")
  .text(" ").prop({"disabled":true,"selected":true});

And this is the code added in the Onready Function.
jQuery("#"+this.questionId+" select option:first-child").prop({"disabled":true,"hidden":true});

On android the results are as expected, but on iphone the code doesnt seem to work. What can I do.